Hard Disk Drive

 The hard disk drive is the data center of the computer. All of your programs are stored here. The hard disk drive is long-term storage where information is stored permanently. When you use a word processing program, the computer loads the instructions from long-term storage (your hard disk) into short-term memory.

Hard disk speed determines how fast your computer starts up and loads programs. The hard disk is called the C drive on most computers.

Optical Disc Drive
An optical disc drive is a peripheral device that reads data stored on optical discs. Some drives can only read from discs, but often drives are both readers and burners. CD and DVD drives are common optical drives. From inside the computer, optical drives look very similar to hard disk drives.

Expansion Slots Expansion Card
An expansion card is a card which you can install to expand a computer's capabilities. Expansion cards are inserted into expansion slots on the motherboard. For example, your computer's video card is an expansion card which plugs into the expansion slots.

Video card
The video card is responsible for what you see on the monitor. If you like playing graphic-intense games on the computer, a good video card is important to you. The main function of the video card is to generate and output images to the computer screen. Better graphics card equals better performance when playing games or working on a high resolution monitor.

Sound Card
The sound card, also called an audio card, is another type of expansion card. It lets the computer play sounds through speakers. Some motherboards feature integrated sound, and do not require a separate sound card..