COMPUTER SOFT WARE

a) System soft ware
 Language processor
 Programing language
 Utilities
 Operating System

b) Application soft ware
• Word processor 1 (launching & mastering key board)
• Spread sheet1 (launching & addition ,subtraction , division , and multiplication)
• presentation soft ware1 ( launching & adding slides ,deleting slides<between, before,
and after>)
• Database1 (launching &creating simple table, form ,query and report<ignore calculate
field>)
• Electronic publication1 (launching the publication & writing in text box)
COMPUTER SOFT WARE
Software is a set of electronic instructions that tells the computer how to do certain
Mention any three characteristics of computer software.
 Computer software is intangible
 Computer software gives instructions/procedures to computers
 Computer software is copyrighted
 Computer software can be installed
 Computer software is executable
 Loads into Memory when running
 All software has a source Code written by a programming Language.
The differences between freeware, shareware, and public-domain software based on their
costs and copyright restrictions.
Freeware is copyrighted software that is free for use.
Shareware is copyrighted software that is free for a trial period of time.
Public-domain software is free software that has no copyright restrictions.

Categories of computer soft ware

Computer software are divided into two categories that is
1.System soft ware
2.Application soft ware
Application soft ware
-Application software tells the computer how to accomplish tasks the user requires, such as creating
a document or editing a graphic image.
-Application software refers to programs that perform specific tasks for users (e.g., word
processing).
Some important kinds of application software are:
-Word processing programs
-Spreadsheet software

-Database management
-Graphics programs
-Web design tools and browsers
-Communications programs
-Entertainment and education
-Presentation programs
-Networking software
-Internet applications

-Multimedia authoring

Word processing

Kinds of jobs that are most appropriate to use a word processor.
1) Creating form letters, memos, or reports.
2) Creating Web pages.
Special features that are normally provided with a word processor.
1) Word wrap
2) Mail merge
3) Spelling check
4) Find and replace
How a word processor works differently when compared with a mechanical typewriter.
1) A word processor prints the entire document at a time while an ordinary typewriter prints one
character at a time.
2) A word processor automatically moves the cursor to the beginning of the next line when text
extends beyond the right page margin while the user needs to advance the lever manually when
using an ordinary typewriter.
Advantages of using a word processor over a mechanical typewriter.
1) Easy and fast to make changes to the document.
2) Convenient to create form letters and mailing labels.
Moving Text Verses Copying Text
-The original text remains in its old place when it is copied and pasted to a new location of the
document.
-The original text is removed from its old place if it is moved to another location of the
document.
Word Processing
 Is the creation of documents using a word processor.
 Using a computer to create, edit, and print documents.
 Refers to the use of a computer and word-processing package or word-processor to type text
documents.
Word Processor
 A word processor is an application software program capable of creating, storing, and
printing documents.
 Is a computer application used for the production (including composition, editing, formatting,
and possibly printing) of any sort of printable material.
 Software that is designed for the entry, editing, and printing of documents.
Footer
Text that appears in the bottom margin of each page of a document.
One or more lines of text that appear at the bottom of every page of a document.
A design element printed at the bottom of a page of text.
Header
Text that appears in the top margin of each page of a document.
One or more lines of text that appear at the top of every page of a document.
A design element printed at the top of a page of text.

The head teacher of your school announces that the secretaries are going to start using
computer based word processors instead of typewriters.
State two reasons why this change may worry some secretaries and staff
 Word processors could lead to unemployment of excess secretaries since work which
could need many people using typewriters to -do can be quickly accomplished by only one
person.
 Word processors require computer literacy and IT skills which many secretaries don’t
have.
 Word processors could lead to eye disorders caused by continuous looking at a light
emitting monitor screen.
 No work can be done with word processors when electricity is off.
 Word processors operate in an environment full of viruses and meltdowns which can lead
to deletions and loss of data.
 Word processors require purchase of expensive machines such as computers, printers, etc.
Apart from Microsoft office word,

state two examples of word processing packages you know
WordPerfect
Lotus Word Pro
Word Star
OpenOffice.org Writer
Abiword
Word Pad
Kingsoft Writer
KWord

What is mail merge?

-The process of combining a form letter with a list of names and addresses to produce
individualized letters
-Mail merge is a software function describing the production of multiple (and potentially
large numbers of) documents from a single template form and a structured data source.
Name three ways in which mail merge can be useful:
-Easy to make a change to a single letter and for that change to happen in every letter e.g. change
the date
-Thousands of letters can be produced very quickly
-Much easier to proof read just one letter than thousands of individual letters
-Letters can be sent to people who meet specific criteria
State the word processing features you know
20(i) Insert text
(ii) Delete text
(iii) Copy / Duplicate /Copy and
Paste text
(iv) Move / Cut and Paste text
(v) Mail Merge
(vi) Search/Find and Replace
(vii) Word wrapping
(viii) Headers and Footers
(ix) Spell checker
(x) Thesaurus
(xi) Tables
(xii) Printing
(xiii) Graphics
(xiv) Tables of content and indexes
Name two types of paragraph/text formatting
(i) Left Alignment
(ii) Center Alignment
(iii) Right Alignment
iv) Justified Alignment

The following shortcut keys are used for?

Windows Logo Key – Accessing the Start Menu

CTRL + C – Copying text

CTRL + V – Pasting text

CTRL + B – Bolding text

CTRL + I – Italicizing text

CTRL + U – Underlining text

Electronic spread sheet

Qn.Define the term Electronic Spread Sheets
A program which organizes information into rows and columns so that it can be manipulated on
easily
Explain any five features of a spreadsheet application.
 Insert text: Allows you to insert text anywhere in the spreadsheet.
 Delete text: Allows you to erase characters, words, charts, or worksheets as easily as you
can cross them out on paper.
 Cut and Paste: Allows you to remove (cut) a section of text from one place in a spreadsheet
and insert (paste) it somewhere else.
 Copy: Allows you to duplicate a section of text.
 Page layout: Allows you to define various page sizes and margins.
 Search and Replace: Allows you to direct the spreadsheet to search for a particular word or
phrase. You can also direct the spreadsheet application to replace one group of characters
with another everywhere that the first group appears.
 Headers, Footers, & Page Numbering: Allows you to specify customized headers and
footers that the spreadsheet file will put at the top and bottom of every worksheet. The
spreadsheet automatically keeps track of page numbers so that the correct number appears
on each page.
 Merges: Allows you to merge text from one file into another file. This is particularly useful
for generating many files that have the same format but different data.
 Spell Checker: A utility that allows you to check the spelling of words in a spreadsheet file.
 Print: Allows you to send a spreadsheet file to a printer to get a hardcopy or many
hardcopies as you would like.
 Thesaurus: A built-in thesaurus that allows you to search for synonyms (words with similar
meaning) and antonyms (‘opposites”) without leaving the word processor.
 Graphics: The spreadsheet application permits the addition of various types of graphics,
such as bar charts, line charts, clip art, and photographs.

Briefly explain five advantages of using Microsoft Excel.
-The ability to reuse the data as many times as required
-The ability to automatically recalculate the spreadsheet
-The ability to share the data from one application to another
-The ability to be able to apply different types of fonts and cell formatting to your
spreadsheet
-The ability to be able to include drawing objects such as photos, lines, Excel art, cartoons,
moving and text and even video
-The ability to spell check the whole spreadsheet in one go or at once
-The ability to add up and apply different formulas to your spreadsheet
-The ability to carryout What If scenarios in “real time”
State five examples of Electronic Spread Sheets software known to you
• Lotus 1-2-3
• Microsoft Excel
• VisiCalc
• Frame works
• Microsoft works
• Quattro-pro
• OpenOffice.org Calc
• Web based spreadsheets
• Apple Numbers
Name three Components of a spread sheet
• Worksheet:
• Database
• Graph
What is the difference between a cell and cell reference?
A cell is an intersection between a column and a row
Cell reference is a combination of the column letter and the row number
Name the three types of data that can be entered into a cell.
• Labels (text)
• Values (numbers)
• Formulae
What is a formula a term used in computer studies?
A formula is an instruction that tells the computer to work out the answer for the value
entered.
Outline three types of formulae you know
 Numeric Formulae
 Logical Formulae
 Text Formulae
Define the following computer terminologies
i. Range
This group of adjacent cells; vertical or horizontal
ii. Worksheet
This is the biggest range because it consists of all the cells in a worksheet.

Work book
This is the collection of various worksheets
Worksheet Frame
This consists of columns ranging from A-IV…end and Rows ranging from 1-
16384…. end
Worksheet tabs
These indicate whether the file consist of more than one worksheet
Cell address
The reference to particular cell
Range address
The reference which has a format of top-left cell address: bottom-right cell address
label
A label is a text entry
A Value
A Value is a piece of data that can be used in calculations
software
Set of instructions and programs that instruct the computer hardware on what to
do.
Cell
 Small box in an Excel worksheet.
 Intersection point of the row and column.
 Where a row meets with the column.
Worksheet
 A single page of workbook or spreadsheet file.
 A single working area in a spreadsheet program, consisting of a grid of lettered columns
and numbered rows.
 Is a grid of columns and rows
Workbook
-A file that contains a series of Worksheets
-A spreadsheet document that contains one or more worksheets.
-Collection of related spreadsheets that are saved as one file.
Mixed Formula
is one which Contains both absolute and relative arguments.
How is Relative addressing different from absolute addressing in a spreadsheet program?
For relative addressing, the cell address (e.g., B1+C1) will be self-adjusted when the formula is
moved or copied to another cell (e.g., B2+C2).

For absolute addressing, the cell address (e.g.,
$B$2) is always fixed.
Features that are normally provided with a spreadsheet program.
1) Automatic recalculation
2) Charting
Advantages of using a spreadsheet program over a manual worksheet.
1) The rest of the worksheet is recalculated whenever data on a worksheet is changed.
2) Operation is fast with the help of built-in functions and macros.
Suggest a suitable chart type for each of the following presentations.
a) Monthly expenditures on different categories of a family
b) Number of car accidents in each month throughout a year
c) Distribution of heights of students in a school
d) Body temperatures of a patient recorded every two hours on a particular day
a) Pie chart b) Bar chart c) Histogram d) Line graph
Describe three ways in which personal data stored on a computer can be misused
-Data could be deleted (e.g. your bank balance could be wiped out)
-Data could be changed (e.g. you could end up with a criminal record, for something you
didn’t do)
-Data could be used for blackmail (e.g. your school record might contain information that you
are embarrassed about, and someone might threaten to reveal it to the press!)
-Data could be used to help someone impersonate you (e.g. they could apply for a bank loan
in your name). This is known as Identity Theft
State two ways of preventing misuse of personal data stored on a computer
Encrypt files, especially when taken out of the office (e.g. on a memory stick, or sent via e-
mail)
-Use strong passwords
-Lock your computer when you are away from it
-Always shred printouts that contain sensitive data

An absolute cell reference is one that always refers to a spreadsheet cell in a specific location
and cannot change when copied to other cells. For example $A$1, $AD$126, etc. (has both
column letter and row number fixed)
While
A mixed cell reference is one that both relative and absolute arguments. It has either an
absolute column or a relative row e.g. $B4, or a relative column and an absolute row e.g.
B$4. Only the relative argument changes when the reference is copied to other cells
Discuss four merits and two demerits of using electronic spreadsheets over manual
spreadsheets.
Merits:
• Easy to make changes and corrections (ease of edit and format) to data on the worksheet.
• Electronic spreadsheets can perform mathematical, statistical, and financial calculations quickly
and accurately.
• The rest of the worksheet is recalculated whenever data in one place changes.
• Spreadsheets have built-in functions and macros which made work easy.
• Calculation is always accurate, provided that data and formulae entered are correct.
• They offer different options of data presentation such as pie charts, bar graphs, etc.
• They are very useful for applications that require modeling and what-if analysis.
• They easily filter, sort, and arrange data in alphabetical order for better organization.
• Workbooks can be saved in soft copies that can be easily modified and reused in future.
Demerits:
• Need for specialized software and hardware which is expensive.
• Spreadsheets require enough time for training and practicing before use.
• There is a lot of complexity surrounding formulas, functions and their arguments.
• May lead to loss of data. Computers are prone to system errors, power outages and virus
infections. These problems also can affect access to your electronic spreadsheet; in extreme
circumstances, it could mean a total loss of data.
• Difficulty in finding Data Mistakes. Electronic spreadsheets are known for having numerous
fields, sometimes in different sizes, making it look like a screen full of small boxes. Working
with such a large volume of data at one time makes it challenging to spot and correct errors
within the document.
• Difficult printing: Obtaining hard copies becomes very hard especially when the worksheets
are wide as compared to the available page sizes.

Electronic presentation

Electronic Database

Give two examples of database management programs
Microsoft Access
FileMaker Pro
Lotus Approach
dBase
Paradox
Mention four merits of using electronic databases
 Data Integrity – By having one location for the data, it is more convenient and easier to
make sure that the stored data is correct. A database can also be set up to verify that input
data is correct for the type of field.
 Data sharing – Computerized databases can be easier to share between a large of group of
people over vast locations. For example, the counters at the banks all share the same
customer accounts information.
 Data security – The computerized database can be shared with everyone, and only allow
authorized people to make changes or look at confidential reports in the database.
 Editing / keeping the Data Current – By making changes in a single location all available
data is kept up to date. Instead of having to change attendance records in different files (class
roll, duty roll, etc) changing it in one location means all information is current.
 Tables – Tables can be created to store data. When new relevant information needs to be
included in a database tables can be easily modified to include new files.
25 Queries – Queries can be used to create custom views of data. Custom views allow you to
limit the data to only those items you want to see. You can even sort the information so it is
easier for you to find items.
 Reports can be generated to display the information in a prettier format.
With Examples, distinguish between an Absolute cell reference’ and a Mixed cell
reference.

The database below contains data about items that have been ordered from various

(a) State the data types of the fields in the given table.
(i)
SUPPLIER ……………..Text………………
(ii)
CODE …………………Number……………
(iii)
DELIVERY DATE …………Date/Time…
(iv)
PRICE ………………………Currency………
(b) The following search condition is input
(CODE = 5613) AND (PRICE <100).
Write down the output using only the SUPPLIER field.
……………………………………MO18…………………
(c) Write down a search condition that will search for all items with a price more than ¥50
that will be delivered in October.
 (PRICE > 50) AND (DELIVERY DATE = Between #1/10/07# And #31/10/07#)
 (PRICE > 50) AND (DELIVERY DATE >=#1/10/07#)
 (PRICE > 50) AND (DELIVERY DATE >=#1/10/07# And <=#31/10/07#)
 (PRICE > 50) AND (DELIVERY DATE =Like “**/10/**” )
(i) What is a primary key?
 A primary key refers to one or more fields whose value(s) uniquely identify each
record in a table.
 A primary key is a column or combination of columns whose values uniquely
identify a row in a database table. The primary key(s) have a unique value for
each record or row in the table.
(ii) Which field in the above database can act as a primary key?
 SUPPLIER field.
Advantages of the database approach over manual file processing.
1) Reduced data redundancy—a centralized database stores all related data in one location,
which reduces duplicate data.
2) Improved data integrity—changes are made to one file instead of multiple files, which reduces
the possibility of introducing inconsistencies.
Describe briefly the difference between a flat file database and a relational database. Give two
advantages of a relational database over a flat file database.
-A flat file database is made up of only one table.
-A relational database can take information from two or more database tables and combine them
into a new table or report through the use of a key field.
Advantages of a relational database:
1) Can access and combine information from more than one table.
2) Changes made in one database table will be reflected in related tables without additional
modifications.
Describe briefly the following terms in a DBMS: a) Record b) Field c) File/Table d)
Database
a) A record contains information about a given person, product, or event.
b) A field contains a specific piece of information within a record. c) A file/table is a collection
of related records.
d) A database is an organized collection of integrated files/tables

Give two advantages of coding data in a DBMS.
1) Speed up data entry.
2) Save space for storage.
Describe briefly how fixed length records different from variable length records. Give one
advantage and one disadvantage for each of these record types.
Fixed length records—each record takes up the same space and each field uses all the space
allocated, even if it is not necessary.
Variable length records—only the actual data is stored with no extra space added. A marker
(e.g., a comma ‘,’) separates each field.
Advantage and Disadvantage of Fixed length record

-Easy to locate where a record is. Waste
storage space.

-Variable length record Save storage space.
Slower processing
Describe briefly in two ways how serial access files are stored differently from random
(direct) access files. Explain briefly why random file access is faster than serial file access.
1) A serial access file is stored as a series of records one after another but a random access file
stores its records based on their calculated values from the key field.
2) Serial access files can be stored on disk or on tape, but random access files can only be stored
on tape. To locate a particular record in a serial access file, all the preceding records must be
processed. The location of any record in a random access file is calculated directly from its key
field, all the earlier records need not be processed, which results in faster processing
 How is a sequential file different from a serial file?
-A serial file is stored as a series of records one after another.
-A sequential file is a serial file with the key field sorted into some order.

How is data verification different from data validation? Name two data verification
techniques and two data validation techniques.
Data verification is the checking for mistakes when data is copied from one place to another (i.e.,
transcription errors).
Examples of data verification technique:
1) Visual check
2) Enter the data twice by the same person or by two different persons.

Data validation is the checking of input data for errors (e.g., of the correct data type) before
processing.
Examples of data validation technique:
1) Range check
2) Check digit
Describe briefly the following validation checks:
a) Presence check
b) Length check
c) Range check
d) Type check
e) Check digit
a) Presence check is to make sure that data is actually present.
b) Length check is to make sure that the number of characters entered is within the limit.
c) Range check is to make sure that the data entered lies within a certain range.
d) Type check (also known as character check or alphanumeric check) is to make sure that the
data entered is of the correct data type (e.g., numeric or alphabetic).
e) A check digit is an extra digit appended to a code consisting of a series of numbers or
characters to detect errors arising from transcription.
Suggest one field in a DBMS of a school that is most appropriate to use the following
validation checks:
a) Range check
b) Check digit
c) Type check or alphanumeric check
d) Presence check or mandatory check
Solution
a) Date of birth
b) HKID number
c) Form
d) Name of student
What is a check digit? Give two examples of fields that are most appropriate to use check
digit for data validation. Why is each digit of such fields is usually multiplied by a different
weighting factor?
-A check digit is an extra digit appended to a code consisting of a series of numbers or characters
to detect errors arising from transcription. Examples of field most appropriate to use check digit
for data validation:
1) HKID number
2) ISBN number of a book Each digit is usually multiplied by a different weighting factor to
avoid transposition errors (e.g., entering 123465 for 123456).
Suggest one way to avoid data input error for each of the following fields on a screen
form.
a) Sex
b) Country Limit the choices of input by:
Solution
a) Using radio buttons for selecting sex.
b) Using combo box for selecting country from the drop down list.
Give two advantages of a screen form over a paper form.
1) Can use screen controls such as combo boxes, radio buttons, or list boxes to limit the number
of choices.
2) Have menus and toolbars to make the selection of actions easier.
Suggest two occasions that an employee’s record in a database needs to be updated.
1) When the marital status of the employee has changed.
2) When the phone number or the address of the employee has changed.
What is a query? What is a query language? What is SQL?
A query is a request for specific data from a database.
A query language consists of English-like statements that allow a user to specify the data to
display, print, or store.
SQL (Structured Query Language) is a query language that is supported by most relational
database management system (DBMS).

How is a master file different from a transaction file? What must be done to a transaction
file before it can be used to update a master file?
-The master file of a DBMS is a data file containing relatively permanent records that are
generally updated periodically.
-The transaction file is a temporary file that holds all changes to be made to the master file,
such as additions, deletions, and revisions. A transaction file has to be sorted before it is used to
update the master file

What is file merging? What must be done to the files before merging?
File merging is to create a single file from two smaller files.
-The two original files have to be sorted in key field order before merging

Describe briefly what is meant by top-down design in the system development process.
Top-down design breaks down a problem into sub-problems, and the sub-problems are broken
down further until they are fairly easy to solve.
State four ways in which an analyst could gather information to investigate a problem.
1) Questionnaires
2) Interviews
3) Group discussions
4) Observations
Name four considerations that should be included in a feasibility study.
1) Information on costs (initial and long-term).
2) A time frame for implementation.
3) Hardware and software required.
4) Staff issues such as training, redundancies, or extra labour required.
In the system development process, the test plan should include the test data, the expected
result, and the actual result. Describe briefly how the test data is chosen. Test data should
include:
1) Normal data that the system is designed to accept.
2) Extreme data that is of the right type but outside the normal range expected.
3) Invalid data that is not accepted by the system.
Describe briefly how user documentation is different from technical documentation.
-User documentation is provided by the developer to help the user get the best out of the
software.
-Technical documentation is provided to help programmers who work on the software in the
future.
Electronic publication

System soft ware

 This is the types of software design to manage the operation of computer its devices.
 Programs that control operation of computer
Why system software is also important for application software to work properly.
System software consists of programs that control the operations of the computer and its
devices. It also serves as the interface between the user, the application software and
hardware.
An operating system

Types of system soft ware
 Operating system
 Utilities
 Programing language
 Language processors
Operating system
-This is a set of programs containing instruction that coordinate all the activities
among the computer hard ware devices Examples of operating system

-This is the is the computer software that coordinate the operation of all hard ware and
software component of the computer
Linux
Window seven
Window Eight
Window 10
Window xp
Macintosh
Obuntu
Functions of operating system
-Manage and allocate computer resources.
-Start the computer
-Control input and output devices
-Manage computer memory usage
-provide a user interface
–Schedules computer operations
-Provide a working environment for all computer applications
-control a network
-administer security
-provide file management and other utilities
What is a user interface?
 Controls how you enter data and instructions and how information displays on screen
a) With a command-line interface,
 a user types commands or presses special keys on the keyboard to enter data and
instructions
b) What is a graphical user interface (GUI)?
 User interacts with menus and visual images such as icons and buttons
 What is memory management?
 Optimizing use of random access memory (RAM)

How does an operating system schedule jobs?
 Adjusts schedule based on job’s priority (A job is operation the processor
manages)
 Receiving data from input device
 Processing instructions
 Sending information to output device
 Transferring items between storage and memory
How does an operating system monitor performance?
 Provides program, called performance monitor, that assesses and reports
information about system resources and devices
What is a network operating system?
Allows users to share printer, Internet access, files, and programs on a network What is
Symbian OS?
 Open-source, multitasking operating system designed for smart phones
 Make telephone calls, save appointments, browse Web, send and receive email
and faxes, and more
What is an embedded operating system?
 Found on most mobile computers, PDAs, and other small devices
 Windows CE .NET is scaled-down version of Windows
 Windows Mobile 2003 for Pocket PC
 Palm OS for Palm, Visor, and CLIE
What are examples of network operating systems?
NetWare Designed for client/server networks
Windows Server 2003
Linux

UTILITIES

Def. Utility are additional essential software that is design to assist either application or system
soft ware
Utility software are broadly sub divided into two
• system utility soft ware
• application utility soft ware
System utility software is that software that further enhances the operation of system software
e.g. device drivers
Application utility soft Ware is that software which enhance the operation of application soft
ware
Example of common utilities soft ware
• File defragmentation
• Data compression
• Backup
• Antivirus
• Screen savers
• Sort merge utility
• File compression utility
• Diagnostic utility
What is a personal computer maintenance utility?
 Identifies and fixes operating system problems and disk problems
 Some continuously monitor computer to identify problems before they occur
What is a file compression utility?
 Shrinks size of files to free up room and improve performance
 Compressed files are sometimes called zipped files
 Two popular utilities: PKZIP and WinZip What is a personal firewall?
 Protects personal computer from unauthorized intrusions
 Monitors all transmissions to and from computer
What is a virus?
 Potentially damaging computer program
 Affects computer without user’s knowledge
Programing language
Programing language are means of passing instructions to computer system using specific
predefined words and symbols arranged in a logical manner .
Function of programing language
It is used to provide a suitable interface for the design and production of a set of instruction
called a program
Categories of programming language
There are two basic categories i.e.
-The low level language
-The high level language
Low level language
The low level languages are language used for designing programs or instruction for the
processor
There are two types of low level language
 Machine code
 Assembly language
Machine code
Machine code; this is referred to as first generation language because instruction must be
written in binary format.
Assembly language
Assembly language; This is referred to as second generation language because combination of
bits are represented by partially meaning full words to human e.g.
Add for addition, SUB for subtraction etc.
Language processors
Language processor are soft ware used to convert high level language into low level language
that is capable of being understood by the processor Examples of language processors
1. Compiler
2. Assembler
3. Interpreter
4. Linkers
5. Debuggers
Compiler
Is one of the major language processors that translate a program written in a higher level
language
There are of two kinds native and cross compiler
Native compiler; is that where the resulting program can only run on the same plat form as the
language
Cross compiler; is that which compile programs capable of running on other platform
Assembler
These are language processor that translate assembly instruction into machine code (binary
format)
Interpreter
An interpreter is that which execute and analyzes the input program before passing on control to
the processor.
Debugger
Is that software program that locates bugs (errors) in another computer program?
A device driver
A device driver is a small program that tells the operating system how to communicate with a
device
Examples of devices that may require a device driver to work properly:
1) Mouse
2) Printer
3) camera

Virtual memory verses physical memory.
With virtual memory (VM), the operating system allocates a portion of a storage medium,
usually the hard disk, to function as additional RAM. Because the access time for any storage
medium is very much slower than that of memory, virtual memory is slower than physical
memory.
Advantages of using a print spooler.
1) By spooling print jobs to a buffer, the processor can interpret and execute instructions while
the printer is printing documents.
2) Spooling also allows sending a second job to the printer without waiting for the first job to
finish printing.
Multitasking verses multiprocessing operating system
A multitasking operating system allows a single user to work on two or more applications that
reside in memory at the same time.
A multiprocessing o