1. ELEMENTS OF A
COMPUTER SYSTEM
HARDWARE
SOFTWARE
PEOPLEWARE
DATA

2. HARDWARE: The physical components of a computer system
It refers to the tangible devices that can be seen, touched and felt
The hardware that makes up the most basic computer system includes the monitor, keyboard and a system unit
Physical components fall into five categories:
Input devices
System unit
Secondary storage
Output devices
Communication devices

3. INPUT DEVICES Mouse Keyboard FIVE CATEGORIES OF HARDWARE:
Translate data and programs that humans can understand into a form that the computer can process.
Keyboard
Looks like a typewriter keyboard, but has additional specialized keys.
Mouse
Is a pointing device that typically rolls on the desktop.
It directs the insertion point or cursor on the display screen.
Has one or more buttons for selecting commands
Also used for drawing figures.

4. SYSTEM UNIT Central processing Unit (CPU)
Is the electronic circuitry housed within the computer cabinet
The two of the most important components of the system unit are:
Central processing Unit (CPU)
Controls and manipulates data to produce information.
A microcomputers CPU is contained on a single integrated circuit or microprocessor chip.
It is like the brain of the computer which controls the whole computer.
It also thinks for the computer with the help of the human using it.
The central processor performs calculations, compares data and produces results.
It has two components: the control unit and arithmetic-logic unit

5. Control Unit:
tells the rest of the computer system how to carry out a program’s instructions.
it directs the movement of electronic signals between memory and the arithmetic logic unit
it also directs these control signals between the CPU and input and output devices
Arithmetic-Logic Unit
usually called the ALU, performs two types of operations – arithmetic and logical
Arithmetic operations are the fundamental math operations: addition, subtraction, multiplication and division.
Logical operations consist of comparisons. That is, two pieces of data are compared to see whether one is equal to (=), less than (<), or greater than (>) the other.

6. Memory ( Primary Storage or Random Access Memory)
Main memory (internal storage)
Holds data and program instructions for processing the data.
It holds the processed information before it s output.
It is sometimes referred to as temporary storage
It is located in the system unit on tiny memory chips.

7. Secondary Storage It also holds data and programs permanently.
It supports the main memory.
It stores data and programs for future use.
This type of memory stores the information on storage media such as floppy disks and CDs
Floppy disks ( also known as diskettes)
widely used to store and transport data from one computer to another.
called as floppy disk because data is stored on a very thin flexible or floppy plastic disk
Hard disks
are typically used to store programs and very large data files
Have a much greater capacity and are able to access information much faster than floppy disks.

8. is relatively new and evolving format
Optical disks
Use laser technology and have the greatest capacity.
There are two basic formats or types of optical disks. CD (compact disks) and DVD ( Digital Versatile Disk)
CD (compact disk)
used to distribute large databases and reference, to back up large data source, and to create, store and edit multimedia presentation.
DVD ( digital versatile disk or digital video disk)
is relatively new and evolving format
capacity is far greater than CDs.
can be used for all the things that CDs are used for, plus they are used to distribute full length motion pictures.

9. OUTPUT DEVICES
Are pieces of equipment that translate the processed information from the CPU into a form that humans can understand
Monitor or video display screen
Resembles a television screen
It displays the result of different commands given by the user.
It shows how the computer answers the commands and show results of what you are doing
The output seen in the monitor is called as softcopy
Printer
a device that produces printed paper output
it produces images on paper which have created in a computer
the printed output is called as hardcopy

10. COMMUNICATIONS DEVICE
Sends and receives data and programs from one computer or secondary storage device to another
Many microcomputers use a modem
Modem
Is a device which converts the electronic signals from the computer into electronic signals that can travel over a telephone line. A modem at the other end of the line then translates the signals for the receiving computer.

11. SOFTWARE another name for programs
includes the programs which the users use to help them finish their work fast.
it includes instructions that tell the computer how to process data
is a set of programs or procedures associated with the computer system.
Two kinds of software:
System Software
Is background software that helps a computer manage its internal resources.
are programs designed to directly or indirectly support program processing
Consists of utilities, device drivers, language translators, and operating systems.
deals with the physical complexities of computer hardware.

12. Operating System
Is a group of computer programs that help your software control your hardware
DOS or Disk Operating System is one of the most well known OS
Manage resources, provide user interface, and run applications
has three basic functions:
Resources: coordinates all the computer’s resources
User Interface: users interact with application programs and computer hardware through a user interface.
Applications: programs which load and run applications such as word processors and spreadsheets.

13. Application Software
Performs useful work on general purpose problems.
Designed to be used by many people to do the most common kinds of tasks.
also known as the basic applications
There are two type of application software: Basic application and the Advanced application

14. Basic Applications:
Browsers: used to connect to remote computers, open and transfer files, display text and images, and provide an interface to the Internet and the Web.
Word Processor: used to create, edit, save, and print text-based documents
Spreadsheet: used to analyze, organize, manipulate and graph numeric information
Database management system: organize and manage data and information
Presentation graphics: are use to create professional and exciting presentations

15. Advanced Applications
Multimedia: integrate video, music, voice, and graphics to create interactive presentations
Web publishers: create interactive multimedia Web pages
graphics programs: create professional publications, draw, edit, and modify images
Virtual reality; create realistic three – dimensional virtual or simulated environments
Artificial intelligence: simulated human thought processes and actions
Project managers: plan projects, schedule, people , and control resources

16. PEOPLEWARE the people involved in the data processing cycle
known as the users or end users -any person who can manipulate and use the computer system and its programs

17. DATA consists of the raw, unprocessed facts.
There are three types of files:
Document files: created by word processors to save documents such as memos, term papers and letters.
Worksheet files: created by electronic spreadsheets like Excel to analyze things like budgets and to predict sales
Database files: typically created by database management programs to contain highly structured and organized data.