HARDWARE UNITS

MOTHERBOARD (Mainboard)

The motherboard provides connections for all parts of a computer. The memory, CPU,hard drives, optical drives, sound card, video card and other ports and expansion cards all  connect to the motherboard directly or via cables.

CPU (Central Processing Unit)

The central processing unit (CPU) is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system.

     RAM (Random Access Memory)

Random Access Memory (RAM) maintains temporary computer data storage. Also  RAM increases your process speed according to its data transfer rate. Double data rate  RAMs are known to be the fastest RAMS. (ex: DDR, DDR2, DDR3). The faster your RAM  is the more you can cope with various programs at the same time.

HARD DISK DRIVES

It is a storage device with very large capacity, which ranges from 1GB to Terabytes in 

the modernscenario. It is placed in side the cabinet of CPU. It is not a removable drive in 

normal circumstances. It is hidden inside the computer and cannot be seen by us. There can 

be one or more hard disk in the system unit of a computer.

OPTIC DRIVES

CD-ROM – CD RW

CD-ROM (Compact Disk Read Only Memory) reads thet data in the CD.

CD RW (Compact Disk Read Write) not only reads the data in the Cd but also writes 

data in the CD.

DVD – ROM – DVD RW

DVD – ROM (Digital Versatile Disc Read Only Memory) reads the data in the CD
and DVD.
DVD – RW (Digital Versatile Disc Read Write) not only reads the data in the CD but

also writes the data in CD veya DVD.

CARD READER

It is a hardware unit that enables the data in the memory cards to be processed.

FLOPPY DISK

It is a smaller capacity removable storage device. It is made up of thin and flexible

plastic material. This thin plastic film is coated with a magnetic material known as iron oxide 

for recording data and is protected by a hard outer cover.

CARDS

Cards are components added to computers to increase their capability. When adding a 

peripheral device make sure that your computer has a slot of the type needed by the device.

SOUND CARDS

Sound cards allow computers to produce sound like music and voice.

VIDEO CARDS

Allow computers to display video and animation. Recent video cards mostly have 

HDMI support

NETWORK CARDS

Allow computers to connect together to communicate with each other and maintains a 

network jack for ethernet cable connection.

POWER SUPPLY

A power supply unit (PSU) supplies direct current (DC) power to the other 

components in a computer. It converts general-purpose alternating current (AC) electric 

power from the mains to low-voltage DC power for the internal components of the computer 

(220 V to 240 V at 50 Hz)

PC PORTS

Parallel Port

Parallel ports can be used to connect a host of popular computer peripherals like:

• Printers
• Scanners
• CD Burners
• External Hard Drives
• Removable Drives
• Network Adapters
• Tape Backup Drives

The standard parallel port is capable of sending 50 to 100 kilobytes of data per second.

Serial Ports

A serial port is commonly used to connect external modems, scanners or the older 

computer mouse to the computer.

USB (Universal Serial Bus) Port

USB is an industry Standard developed in the mid-1990s that defines the cables, 

connectors and protocols used for connection, communication and power supply between

computers and electronic devices. A sample list of USB devices that you can use today 

includes:

• Printer
• Scanner
• Microphone
• Joystick
• Digital Camera
• WebCam
• Scientific Data Acquisition Device
• Modem
• Speaker
• Telephone
• Video Phone
• Storage Device Such As Zip Drive
• Network Connection

FIREWIRE PORTS

This port was originally created by Apple and standardized in 1995 as the 

specification IEEE 1394 High Performance Serial Bus and is very similar to Universal Serial 

Bus (USB). The key difference between FireWire and USB is that FireWire is intended for 

devices working with a lot more data -- things like camcorders, DVD players and digital 

audio equipment.

PS/2 PORT

It is also called a mouse port. It is used to connect a computer mouse or keyboard. 

Nowadays few computers have two PS/2 ports, one for keyboard (purple) and one for 

Mouse (green).

MONITOR PORT

This connector is used to attach a computer display monitor to a computer's video 

card. The connector has 15 holes.

AUDIO/SPEAKER AND MİCROPHONE SOCKET

At the back of the computer system we can find three small sockets of blue, green and
pink colours used to connect speakers, audio input devices and microphones to the PC
respectively. The connectors for microphone and speakers look like as shown in the adjacent

figure. They are colour coded to help in troubleshooting.

ETHERNET PORT

Is a family of computer networking technologies for local area networks (LANs)

commercially introduced in 1980.

HDMI PORT

HDMI is a compact audio/video interface for transmitting uncompressed digital data.
It is a digital alternative to consumer analog standards, HDMI connects digital audio/video sources to compatible digital audio devices, computer monitors, video projectors, tablet computers, and digital televisions.

EXTERNAL HARDWARE UNITS

KEYBOARD

Most important input device “keyboard” functions as typing alphabets, numbers and
operators, besides it controls the cursor seen on the screen. Another popular type of keyboard
is the wireless keyboard. It may be preferred for its practical usage. A basic keyboard and a

wireless keyboard may seem as below:

MOUSE

The basic function of mouse is pointing to a specific position on the screen. To execute or select different processes on top are two or three buttons. Because of the sound heard when pressing the buttons the pressing operation is called clicking. The mouse should be placed on a flat surface and moved around to control the arrow seen on screen. The arrow indicating the place of the mouse is called “mouse pointer”. Left button executes the operation related to it. Right and middle (scroll) buttons are responsible for private operations in different situations.

OTHER INPUT DEVICE

LIGHT PEN

Used in conjunction with the computer monitors for drawing pictures, pointing and for directly controlling screen operations.

JOY STICK

Used to control cursor on screen. Normally it is used in Games and specially designed simulation software.

MICROPHONE

It is a device used to accept audio inputs from the user.

TOUCH PADS

A touch-sensitive device that allows user to interact with the computer system by touching an area on the screen and also used for technical drawings.

DISPLAY UNITS

MONITOR

The output or the processed result and the typed information are displayed by the monitor. Display types can be classified as:

• Cathode ray picture tube
• Liquid crystal
• Plasma panel
• Touch panel

PROJECTION

Magnifying the PC or TV images, it reflects these images to a wall or a screen.

PRINTERS

Produces paper copy (hard copy) for a document, pictures etc. It gives an output on the paper what we see on the monitor. We can classify printers in two groups as impact printers and non-impact printers.

• Dot Matrix Printer

Uses dots through inked ribbon, very economic and needs very less maintenance cost.

Dot Matrix Printer

An example of a dot matrix printer output

• Inkjet/Deskjet/Bubblejet Printer

Despite their low prices they have high maintenance costs. Using the liquid ink

technology they print the image using circuit-controlled jet of ink. An inkjet sprays the ink

onto the paper in tiny droplets to form text and graphics.

• Laser Printer

It has a technology on combination of laser and Xerox. Dry powder based ink is adhered to a drum through magnetic force and when the paper reaches the drum the ink is realesed on the paper.These types are the fastest devices among the category and have a high-speed quality prints.

Working principle of a Laser printer

Laser printer

IMAGE PROCESSOR DEVICE

SCANNER

Captures digital images of printed documents, graphics or other printed media.

WEB CAMERA

The device used During a web-based video conferencing for transfer of images is called “web camera”. Generally web cameras have low resolution rates.

OTHER OUTPUT DEVICE

HEADPHONES

Headphones are a pair of small loudspeakers, or less commonly a single speaker, held close to a user's ears and connected to a signal source such as an audio amplifier, radio, CD player or portable Media Player. They are also known as stereophones, headsets.

SPEAKERS

Speakers are used to play sound. They may be built into the system unit or connected with cables. Speakers allow you to listen to music and hear sound effects from your computer.

EXTERNAL  STORAGE DEVICE

FLASH FRIVE

This is a type of flash memory storage device of the size of a thumb and can plug into the USB port of the computer. USB flash drives are more compact, generally faster, hold more data, and are more reliable (due to their lack of moving parts) than disk storage.

EXTERNAL HARD DRIVES

External removable hard disk drives offer independence from system integration, establishing communication via connectivity options, such as USB.External hard disk drives are available in two main sizes (physical size), 2.5" and 3.5".While 3.5” external hard drives have DC adaptors, 2,5” external harddrives maintain electricity from the pc it is connected.

HARDWARE TERMS

GENERAL TERMS

ADAPTER

It is an interdevice required to connect two maladjusted device sor connection types.

BACK UP

Having a copy of the current state of the system in an external hard drive, DVD or a blu-ray disc in case of a system failure or crash in any means.

As a priority system files should be backed up.

BANDWIDTH

It is defined as the bitrate transferred in a second. Bandwith affects the whole system’s velocity.

BPS (Bits Per Second)

The unit used to measure the speed of data transfer.

CABLE

It is tool we use to physically connect our computers to other units.

CAPACITY

It is the possible highest transmission rate on a communication channel, circuit or hardware.

CHIP

The name given to the unit made of a semiconductor material and carries thousands of electronic circuit on it.

DEVICE

The name given to a piece of hardware that can be processed.

INTERFACE

A device that provides connection between two different sections.

MOTHERBOARD TERMS

AGP (Accelerated Graphics Port)

It is a connection unit produced by the motherboard manufacturers to maintain more efficiency from three dimensional graphic cards.

ATA (Advanced Tecnology Attachment)

It is a connection standard used for harddisks.

BIOS (Basic Input Output System)

The software on the system run by the microprocessor. This software the system to begin working.

BUS

The name given to the path the data is transferrded in the computer.

DATABUS

The name given to the paths those provide data transfer between processor and memory.

DIMM (Dual In-Line Memory Module)

RAM memory module slots installed on the motherboard.

FSB (Front Side Bus)

Name given to the bus between the processor and memory.

IDE (Intelligent Drive Electronics)

Name given to the interfaces used for connecting the harddisks to the computers.

NORTH BRIDGE

The chip that connects the memory, AGP and South bridge on the computer to processor.

PCI (Personal Computer Interconnect)

The interface that is 32 bites and supporting up to 64 bites allows installation of additional devices and components on acomputer.

ROM (Read Only Memory)

Only readable type of memory.

SATA (Serial ATA)

A type of connection that performs fast data transfer.

SOCKET

Name given to the interface the processor is installed on the computer.

SOUTH BRIDGE

The name of the chip that allows low-speed output and interfaces such as paralel, serial, USB, PS2 to connect to the processor via North Bridge.

PROCESSOR TERMS 

CACHE MEMORY

The name given to the buffer momory. The momories have the fast access speed.

OVERCLOCK

It is the process of running the CPU, graphic card and memory faster than their real speeds.

LEVEL

The term used for levelling the processor memory.

HARD DISK TERMS 

BAD SECTOR

The name given to the sectors on hard drive or floppy disks those became unusable because of disruption.

BOOT SECTOR

Boot sector is the system information part of hard drives and floppy disks.

CLUSTER

The name given to the sector group on hard drive.

JUMPER

The metal bridge used for determining priority in harddisks.

LOGICAL DRIVE

Despite percieved as a drive by user it is a portion of the drive structure.

RPM (Return Per Minute)

It specifies the rotation speed of harddisk drives per minute.

OTHER TERMS 

CARTRIDGE

The ink storage unit used in inkjet printers.

DPI (Dots Per Inch)

It is the number of dot in an inch. It is a unit of measurement became Standard for printers and scanners.

Dot Pitch

The name given to measurement of distance between two dots on our monitors.

GPU (Graphics Processing Unit)

It is a chip that performs image calculations and image processing without transferring them to the microprocessor.

PPM (Page Per minute)

It specifies the number of printer outputs per minute.

Resolution

The number of horizantal and vertical pixels on the screen.