The main components of a computer with brief descriptions.

Main components of a computer

Motherboard – The main printed circuit board (PCB) where all the other system components plug in.

CPU – Central processing unit, each computer has at least one CPU or a microprocessor, which runs instructions contained in computer programs and undertakes input/output operations. The CPU has many parts, including arithmetic and logic (ALU) unit, control unit, registers, etc.

Arithmetic and logic unit – This completes basic calculations (arithmetic) and comparisons (logic). Comparisons are used in sorting and searching operations.

Control Unit – Each machine code instruction is extracted from memory. Decoded and run calling on the ALU when necessary. The output is either written  to the register for fast recall as part of subsequent instructions or back to main memory. The control unit is there to make the rest of the computer hardware do whatever is the result of the completed instruction.

Registers– There are several types of register whithin the CPU are used to store a small amount of data in the form of bytes. This is useful for the ALU so it can work out a calculation from two bytes held in registers. Registers are also used to hold addresses in RAM so the CPU knows where the next machine code instruction will come from and where to send the results of a calculation.

Memory – The RAM is used to hold all the programs that have been started and all opened documents, so the CPU can access them. A large amount of ram allows you to have lots of applications open at the same time and to edit large files such as music and video easily.

Graphics card (or video card) – this is used to make visual images that can be displayed on a monitor.

Sound – Hardware used to drive (send sound signals to) speakers is usually built into the mouseboard.

Heat dispersal – The fan and heat sing are needed by the CPU and other hot parts of the computer so they don’t burn out.

Storage devices – A solid state magnetic drive is needed to keep programs and documents when the computer is switched off. You will need a large storage device if you want to keep the large files such as videos.

Optical drive – An optical drive uses laser light to read data from CDs and DVDs. This optical drive is used to install new software and to make backups.