1. System Unit Components Computer Systems

2. A Hard drive is device for digital data; it can store work and others things off your computer on it, the bigger the hard drive is the more memory the computer can store. The Hard disk is connected to the motherboard. The hard disk is the permanent store of data, a typical hard disk drive two electronic motors and an actuator that writes and reads the hard disk. Hard Drive

3. The Heat sink is a Cooling device that installed in the computer to stop it from getting overheated; heat sinks are also used in air conditioning units and are a important device in a computer. Heat Sink Heat sink

4. The power supply to a computer is its main source of power and it crucial for the computer to run unless it can run off its own battery life e.g. a laptop. If a computers power supply is cut then the system will turn off and work will be lost if not saved. Power Supply

5. The Graphics Card generates output images to a display, different cards offer different added functions for example some allow video capture or TV output.Most computers don’t have graphics but have their own onboard graphics. It connects to the motherboard by ISA,MCA,VLB,PCI,AGP,PCI-X,PCI Express and more. It connects to the display output via VGA,HDMI,S-video and more. Graphics Cards

6. Random Access Memory is a form of computer data storage, it is temporary storage. the RAM disc loses its data when the computer shuts down because its volatile. The Ram connects to the motherboard into the RAM slots, as a CPU loads a program from the hard disk code and data are loaded into the RAM. RAM

7. A port is an interface between are computer to another computer or peripheral devices, a mainly used port is the USB port its is used to connect many devices to the computer. Ports allow the user to connect things to the pc Ports

8. Processor The processor is the part of the computer which processes or deals with the data and processes in the system. The Processor is the heart of a computer The processor carries out instructions from the computer program.

9. The Motherboard is the main printed circuit board in the computer. It has many sockets into which the CPU, memory (RAM and ROM), cards (sound, graphics, network interface etc) and peripheral devices are connected. The Motherboard is essential as a means of connecting all of the computer's parts together. Extra boards, called 'daughter boards' can be plugged into the motherboard. Motherboard

10. Cables are essential in computer systems there are many different types made from different materials. The mains power lead is designed to send power to the system A USB lead allows users to connect devices to the computer A VGA can allow a user to connect a graphics card to the output monitor or screen. Cables

11. A network car allows data to be transferred between the computer and network. A network card has its own unique 48 bit code called a MAC address. There are also wireless network cards which work the same way as a normal network card, but it uses wireless technology. Network Card

12. The BIOS runs as part of the start up sequence when you switch on your computer. The BIOS contains all the code required to control the hardware e.g. keyboard, monitor, mouse. The BIOS is stored separately from the hard disk on a ROM chip. This means that if the computer crashes, the BIOS data is protected. BIOS