Knowing the internal and external components of a Computer System.

1. Computer Hardware
and Software Elements

2. Objectives
• Explain the parts of a computer system
• Identify computer hardware.
• Explain the different hardware available and their functions
• Describe hardware configuration
• List some input units
• Describe the functions of the output units.
• Describe the function of the CPU
• List some auxiliary units
• Describe the functions of the auxiliary memory.
• Define: nibbles, bytes, word and storage size in terms of ‘k’
• Define software
• List various types of software
• Distinguish between low and high level languages
• Define source and object codes
• Identify source and object codes
• Define a translator
• Describe different types of translator: assembler, compiler, and interpreters.
• Identify different types of translators: assemblers, compilers and interpreters.

3. A Computer System
A computer system consists of different units. These units
have their own functions. They are connected with each
other via cables or other medium. These units are
connected with a purpose of smooth operation of
computer. Computer system has four major
1. Input Unit,
2. Processing Unit,
3. Output Unit
4. Storage Unit.

4. Input Unit
The task of Input Unit is very simple – to input data into the
computer. All the devices that somehow enter data in computer are
input devices. We type into keyboard to enter data, click on mouse to
issue commands (input commands into computers), scan images,
record voice, shoot video and many ways a computer gets data into
iSto. , keyboard, mouse, light pen, joystick,
microphone, web cam, video camera
etc. all are input unit device
If we look a bit deeper, it is the input
unit that accepts the user data,
converts it in suitable form (string of
binary digits) –known as encoding – so
that it can be used by computer.

5. Processing Unit
The task of processing unit is to process data. It obtains
data from input unit, performs necessary calculation,
comparisons to produce the result. This unit is often
called the central processing unit (CPU) and consists of
three sub-units – ALU, CU & MU. Processors, co-processors,
Memory cards etc. constitute this unit.

6. Constituent of Processing Unit
• ALU stands for Arithmetic and Logical Unit. This
is the calculating unit of a computer system. The
actual instructions execute in ALU. It performs
mathematical manipulation, logical and
comparative analysis.
• CU stands for Control Unit. It is a sub-unit of CPU
that controls and directs the flow of information
throughout the computer system. So, it is also
known as the nerve center of a computer system.
It is the job of CU to fetch instructions, decode
them and execute.

7. Constituent of Processing Unit
Primary Memory Unit (MU)
This is a part of CPU that handles the storage
facilities of data. Primary memory is also known
as internal memory. It is called primary memory
because this is the only unit through which CPU
accesses data directly. The examples of primary
memory are RAM and ROM.

8. Output Unit
This unit provides results to the user in suitable form.
A computer may output as display on monitor,
projector or produce sound in speaker, or printout
through printer, plotter etc.
These are output devices.
This unit receives data from
processing unit and converts
it in suitable form (decodes –
contrast with encoder, the
input unit) so that the output
is in human readable form.

9. Storage Unit
Storage unit facilitates the data storage in
computer so that it can be kept safe for future
use.
Hard Disk

10. Types of Storage
There are two types of storage –
• primary or main or internal storage
• secondary or auxiliary or external storage
Paper Tapes, magnetic tapes, floppy disk, hard
disk, compact disks, Blu-ray disks etc. are
some examples of secondary storage devices.

11. Primary Storage
Primary storage is a storage location that holds
memory for short periods of times while the
computer is on. For example, computer
RAM and cache are both examples of a primary
storage device. This type of storage is the fastest
type of memory in your computer and is used to
store data while it's being used. For example,
when you open a program data is moved from
the secondary storage into the primary storage.

12. Secondary Storage
Secondary storage is a storage medium that
holds information until it is deleted or
overwritten regardless if the computer has
power.

13. Exploded View of Personal Computer
System

14. Bit
• A 'bit' (short for Binary Digit) is the smallest
unit of data that can be stored by a computer.
Each 'bit' is represented as a binary number,
either 1 (true) or 0 (false).

15. Byte
A 'byte' contains 8 bits, so for example, it could
be stored as 11101001. A single keyboard
character that you type, such as the letter A or
the letter T takes up to one byte of storage.

16. Nible
This is not a very commonly used term compared to
bit and byte. It is the term given to a group of four
bits. Therefore two nibbles make a byte.
The reason it is not very common is because most
microprocessors use groups of 8bits and higher i.e.
They use one or more bytes to process data. Not
many devices make use of a nibble.

17. Software
Also known as Program or Code. Software are
instructions executed by a computer, as
opposed to the physical device on which they
run (the “hardware“ ).
Software is a set of instructions that tells the
computer what to do.
Software can be split into two main types:
•system software
•application software

18. Types of Software

19. System Software
• System software is a program that manages
and supports the computer resources and
operations of a computer system while it
executes various tasks such as processing data
and information, controlling hardware
components, and allowing users to use
application software.

20. System Management Programs
• The system management programs are
programs that manage the application software,
computer hardware, and data resources of the
computer system
• These programs include operating systems,
operating environment programs, database
management programs, and telecommunications
monitor programs. Among these, the most
important system management programs are
operating systems.

21. System Support Programs
• System support programs are the programs
that help the operations and management of
a computer system.
• The major system support programs are
system utility programs, system performance
monitor programs, and system security
monitor programs (virus checking programs).

22. System Development Programs
• System development programs are programs
that help users develop information system
programs and prepare user programs for
computer processing.
• The main system development programs are
programming language translators,
programming environment programs,
computer-aided software engineering
packages.

23. Examples of System Software
Operating Systems are the main examples for system software.
Examples of OS are as follows:
•Linux
•Microsoft Windows
•Mac OS X
•DOS
Other system software are following:
•BIOS Software
•HD Sector Boot Software
•Device Driver Software i.e Graphics Drive etc
•Linker Software
•Assembler and Compiler Software

24. Application Software
• Application software consists of programs that
direct computers to perform specific
information processing activities for end
users.

25. Types of Application Software
• Word Processing Software: This software
enables users to create and edit documents.
Eg MS-Word, Word Pad, Notepad etc
• Database Software: is a structured collection
of data. Database software allows users to
store and retrieve data from databases. Eg
Oracle, MSAccess, etc.
•

26. Other Types of Application
Software
• Multimedia Software:
They allow users to create and play audio and
video files.
• Presentation Software:
The software that is used to display information
in the form of a slide show is known as
presentation software.

27. Other Types of Application
Software
• Enterprise Software:
It deals with the needs of organization processes and
data flow.
• Educational Software:
It has the capabilities of running tests and tracking
progress. It is often used in teaching and self-learning.
• Simulation Software:
Used to simulate physical or abstract systems,
simulation software finds applications in both,
research and entertainment.

28. Other Types of Application
Software
• Simulation Software:
Used to simulate physical or abstract systems,
simulation software finds applications in both,
research and entertainment.
• Content Access Software:
It is used to access content without editing. Common
examples of content access software are web
browsers and media players.

29. Other Types of Application
Software
• Application Suites:
An application suite is an important type of application
software. It consists of a group of applications
combined to perform related functions.
• Information Worker Software:
Individual projects within a department and individual
needs of creation and management of information
are handled by information worker software.