A computer is a programmable machine that receives input, stores and manipulates data, and provides output. It responds to specific instructions and can execute prerecorded lists of instructions (programs). All computers require hardware components like memory, mass storage devices, input devices, output devices, and a central processing unit (CPU). Computers can be classified based on their capabilities as personal computers, portable computers, servers, embedded computers, and supercomputers/mainframes.

1. What is computer?
• IT IS A PROGRAMABLE MACHINE.
The two principal characteristics
of a computer are:
1. It responds to a specific set of instructions
in a well-defined manner.
2. It can execute a prerecorded list of
instructions (a program)

2. What is computer?
A computer is a programmable
machine that receives input,
stores and manipulates data,
and provides output in a useful
format.

3. All general-purpose computers require
the following hardware components:
• memory : Enables a computer to store, at least
temporarily, data and programs.
• mass storage device : Allows a computer to permanently
retain large amounts of data. Common mass
storage devicesinclude disk drives and tape drives.
• input device : Usually a keyboard and mouse, the input
device is the conduit through which data and instructions
enter a computer.
• output device : A display screen, printer, or other device
that lets you see what the computer has accomplished.
• central processing unit (CPU): The heart of the computer,
this is the component that actually executes instructions.

4. Synthesis
• Computers can be classified according to
their capacity. They can be classified as
Personal Computers (PCs), Portable
Computers, Servers, Embedded Computers
and Supercomputers & Mainframes.

5. Classification Description
Single-user, general purpose
computers that are usually found
at home, in school and office
Smaller “on the go” personal
computers that use batteries.
Computers on a network that
provide services to client-
computer services
Can be found inside mostly
commonly used devices to provide
them with “intelligence”
They are big, fast, and expensive
computers that are used for large-
scale data manipulation, updating,
and communication

6. These are single-user,
general-purpose computers
that normally fit on a
desktop and are not easily
transported because of
weight.
Personal Computers

7. Portable Computers
• These are smaller, “on
the go” personal
computers that run on
batteries, such as
laptops, notebooks,
and
palmtops/handhelds.
is a computer that is designed to be moved from
one place to another and includes a display and
keyboard. Portable computers, by their nature, are
microcomputers.

8. Server
• These are computers
on a network that
provide services to
client computer-
service such as web,
mail, file archives.

9. Embedded Computers
• Embedded computers can be compared to
"computers on a chip". All in one so to speak.
You will find them in all kind of devices that
surround us. Washing machines,
ticketmachines at the subway, cellphones,
camera's, cars, motors, sewing machines,
clocks. Everywhere needing something to
regulate, control of check something.

11. Supercomputers and mainframes
• Supercomputers have
been designed to do
complex calculations
at faster speeds than
other computers.
The only difference between an ordinary computer
and supercomputers is that supercomputers have their
CPUs opened at faster speeds than standard
computers.

12. Can you beat
lola Techie?

17. All general-purpose computers require
the following hardware components:
• memory : Enables a computer to store, at least
temporarily, data and programs.
• mass storage device : Allows a computer to permanently
retain large amounts of data. Common mass
storage devicesinclude disk drives and tape drives.
• input device : Usually a keyboard and mouse, the input
device is the conduit through which data and instructions
enter a computer.
• output device : A display screen, printer, or other device
that lets you see what the computer has accomplished.
• central processing unit (CPU): The heart of the computer,
this is the component that actually executes instructions.

18. Components of the Computer System
1. Hardware
2. Software
3. Peopleware

19. Input Devices

20. Output Devices

21. Storage Devices

22. Network Devices

23. CPU

24. Software
• Application
• System
– Utility Software
– Programming Language
– Operating System