2. Definition
an electronic device for storing and processing
data, typically in binary form, according to
instructions given to it in a variable program.
3. Functions
There are basically for basic functions of
computers - input, storage, processing and
output. These are described below: Input:
Receiving or accepting information from
outside sources. The most common way of
performing this function is through the
information entered through the keyboard
and the click of mouse.
4. Input Devices
Keyboard- a computer keyboard is a typewriter device which uses an arrangement of buttons.
Mouse- a computer mouse is a pointing device.
Digital Camera- a camera that produces digital images that can be stored in a computer.
Joystick- a joystick is consisting of a stick that pivots on a base and reports its angle or direction to the
device it is controlling.
5. Processing Devices
Central Processing Unit - a central processing unit (CPU) is the electronic
circuitry within a computer that carries out the instructions of a computer program.
Graphics Processing Unit- a graphics processing unit (GPU), occasionally
called visual processing unit (VPU), is a specialized electronic circuit designed to rapidly
manipulate and alter memory to accelerate the creation of images.
Motherboard- it holds and allows communication between many of the crucial
electronic components of a system, such as the central processing unit and memory, and
provides connectors for other peripherals
Network Card- is an electronic device that connects a computer to a computer
network, usually a LAN.
6. Output Devices
Computer Monitor- a computer monitor is an output device which displays the
information in pictorial form.
Printer -a printer is a peripheral which makes a persistent human-readable
representation of graphics or text on paper or similar physical media.
Projector- is an optical device that projects an image (or moving images) onto a
surface, commonly a projection screen.
Speaker- a speaker is a term used to describe the user who is giving vocal
commands to a software program.
7. Storage Devices
Hard Disk- is a data storage device that uses magnetic storage to store and
retrieve digital information.
DVDs- is a digital optical disc storage format.
Magnetic Tape- is a medium for magnetic recording.
USB Memory Stick- is a data storage device that includes flash
memory with an integrated USB interface.
8. Types of Computers I
Supercomputers- a particularly powerful mainframe computer.
Tower- a computer case, also known as a computer chassis, system unit, base unit, is the enclosure
that contains most of the components of a computer.
Mini Tower- a mini-tower case will typically have only one or two external bays.
Mainframe- used primarily by large organizations for critical applications, bulk data processing,
such as census, industry and consumer statistics, enterprise resource planning, and transaction
processing.
Laptop- a computer that is portable and suitable for use while traveling.
9. Types of Computer II
Desktop computer- is a personal computer that fits on or under a desk.
Microcomputer- a small computer that contains a microprocessor as its central processor.
Minicomputer- a computer of medium power, more than a microcomputer but less than a
mainframe.
Servers- a server is a computer program that provides services to other computer programs in
the same or other computers.
Personal Computer- a computer designed for use by one person at a time.
10. Computer Networks
A computer network is a set of computers connected
together for the purpose of sharing resources. The
most common resource shared today is connection to
the Internet. Other shared resources can include a
printer or a file server.
11. Transmission Media
With guided transmission media, the waves are guided
along a physical path; examples of guided media include
phone lines, twisted pair cables, coaxial cables, and
optical fibers. Unguided transmission media are methods
that allow the transmission of data without the use of
physical means to define the path it takes.
12. Types of Transmission Media I
Wired/Guided
Twisted Pair- is a type of wiring in which two conductors of a single circuit are
twisted together for the purposes of canceling out electromagnetic interference from external
sources.
Coaxial Cable- is a cable used in the transmission of video, communications, and audio.
Optical Fibers- a thin flexible fiber with a glass core through which light signals can be
sent with very little loss of strength.
13. Types of Transmission Media II
Wireless/Unguided
Radio waves- an electromagnetic wave of a frequency between about 104 and 1011 or
1012 Hz, as used for long-distance communication.
Microwave- an electromagnetic wave with a wavelength in the range 0.001–0.3 m, shorter
than that of a normal radio wave but longer than those of infrared radiation.
Infrared- having a wavelength just greater than that of the red end of the visible light
spectrum but less than that of microwaves.
14. Major Parts of the Computer
Motherboard- a printed circuit board containing the principal components of a computer or
other device, with connectors into which other circuit boards can be slotted.
Central Processing Unit- the part of a computer in which operations are controlled and
executed.
Random Access Memory- is a form of computer data storage which stores frequently used
program instructions to increase the general speed of a system.
Hard Drive- a high-capacity, self-contained storage device containing a read-write mechanism
plus one or more hard disks, inside a sealed unit.
Power Supply- is an electronic device that supplies electric energy to an electrical load.
