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. FUNCTION
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
Computer keyboard- - is a typewriter-style device which uses an
arrangement of buttons or keys to act as a mechanical lever or electronic
switch.
Touchpad or trackpad - is a pointing device featuring a tactile sensor, a
specialized surface that can translate the motion and position of a user's
fingers to a relative position on the operating system that is made output
to the screen.
Joystick - is an input device consisting of a stick that pivots on a base and
reports its angle or direction to the device it is controlling.
Digital camera - is a camera that produces digital images
that can be stored in a computer, displayed on a screen and
printed.[1]
5. STORAGE
DEVICES
FLOPPY DISK DRIVE is a piece of computer hardware that reads data
from, and writes data to, a small disk.
HARD DRIVE is a data storage device that uses magnetic storage to store
and retrieve digital information using one or more rigid rapidly rotating
disks (platters) coated with magnetic material.
USB flash drive, also variously known as a USB drive, USB stick, thumb
drive, pen drive, jump drive, flash-drive or USB memory, is a data storage
device that includes flash memory with an integrated USB interface.
MEMORY CARD, flash card or memory cartridge is an electronic
flash memory data storage device used for storing digital
information.
6. OUTPUT DEVICES
INKJET PRINTER
is a type of computer printing that recreates a digital image by propelling
droplets of ink onto paper, plastic, or other substrates.
HEAD PHONES
are a pair of small loudspeaker drivers that are designed to be worn on or
around the head over a user's ears.
PROJECTOR or image projector is an optical device that projects an image (or
moving images) onto a surface, commonly a projection screen.
COMPUTER MONITOR is an output device which displays the information
in pictorial form. A monitor usually comprises the display device, circuitry,
casing, and power supply.T
7. PROCESSING DEVICE
Motherboard is the main printed circuit board (PCB) found in general purpose
microcomputers and other expandable systems.
Central Processing Unit (CPU) is the electronic circuitry within a computer that
carries out the instructions of a computer program by performing the basic arithmetic,
logical, control and input/output (I/O) operations specified by the instructions.
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 in a
frame buffer intended for output to a display device.
8. TYPES OF COMPUTERS
SUPERCOMPUTER - IS A COMPUTER WITH A HIGH LEVEL OF COMPUTING PERFORMANCE
COMPARED TO A GENERAL-PURPOSE COMPUTER.
Desktop computer - is a personal computer designed for regular use at a single location on or
near a desk or table due to its size and power requirements.
Mini-Tower - a vertical case, smaller than a tower, designed to house a computer
system standing on a desk or floor.
Mini-Computer - a computer of medium power, more than a microcomputer but less
than a mainframe.
Mainframe - are computers used primarily by large organizations for critical applications,
bulk data processing, such as census, industry and consumer statistics, enterprise
resource planning, and transaction processing.
9. Laptops are folded shut for transportation, and thus are
suitable for mobile use.
Microcomputer is a small, relatively inexpensive
computer with a microprocessor as its central processing
unit (CPU). It includes a microprocessor, memory, and
minimal input/output (I/O) circuitry mounted on a single
printed circuit board.
10. COMPUTER NETWORK
• A computer network or data network is a telecommunications
network which allows nodes to share resources. In computer
networks, networked computing devices exchange data with each
other using a data link.The connections between nodes are
established using either cable media or wireless media.
11. TRANSMISSION MEDIA
• Transmission media is a pathway that carries the information from sender to
receiver. We use different types of cables or waves to transmit data. Data is
transmitted normally through electrical or electromagnetic signals.
• An electrical signal is in the form of current. An electromagnetic signal is series
of electromagnetic energy pulses at various frequencies.These signals can be
transmitted through copper wires, optical fibers, atmosphere, water and
vacuum Different Medias have different properties like bandwidth, delay, cost
and ease of installation and maintenance.Transmission media is also called
Communication channel.
12. TYPES OF TRANSMISSION MEDIA
WIRED MEDIA
Twisted pair cabling is a type of wiring in which two conductors of a single circuit are
twisted together for the purposes of canceling out electromagnetic interference (EMI)
from external sources; for instance, electromagnetic radiation from unshielded twisted
pair (UTP) cables, and crosstalk between neighboring pairs.
Coaxial cable, is a type of cable that has an inner conductor surrounded by a tubular
insulating layer, surrounded by a tubular conducting shield. Many coaxial cables also have an
insulating outer sheath or jacket.
Fiber optic cable is a network cable that contains strands of glass fibers inside an insulated
casing.They're designed for long distance, very high performance data networking and
telecommunications.
13. WIRELESS MEDIA
Radio waves are a type of electromagnetic radiation with wavelengths in the
electromagnetic spectrum longer than infrared light.
Microwaves are a form of electromagnetic radiation with wavelengths ranging
from one meter to one millimeter; with frequencies between 300 MHz (100 cm)
and 300 GHz (0.1 cm).[
Infrared radiation extends from the nominal red edge of the visible
spectrum at 700 nanometers (nm) to 1 mm. This range of wavelengths
corresponds to a frequency range of approximately 430 THz down to 300
GHz.
14. MAJOR PARTS OF THE COMPUTER
CPU
even though there are many add on that make up a computer , here
the simple and basic components that a computer must have.
Random Access Memory
The component in the computer that stores information the computer
needs while it is operating.
Motherboard
provides connections for all the peripheral (child) devices. It's becoming
increasingly common for a motherboard to perform these peripheral functions
without a separate device.
Hard Drive
provides the permanent storage for information. This information
is still recorded when the computer is turned off.