Hard Drive or Hard Disc Drive
This is where all the data is permanently stored on the computer including all programs including the operating system, all files including documents, movies, music and images. As programs are opened the data is moved to RAM to be accessible more quickly.
Solid State Drive
This is an alternative to a hard disc drive. It has no moving parts so is faster and more reliable (less likely to malfunction). SSDs are generally smaller and so suitable for mobile devices.
The motherboard is the main circuit board that connects all the internal components together.
Power Supply Unit (PSU)
Your computer is connected to the mains power (your plug socket) by the PSU. The PSU converts the mains AC to DC power so that it can be used by the components in the computer.
The heat sink is used to quickly disperse heat from the processor. It is a passive device – it does not contain any moving parts and doesn’t do anything apart from sit there (it is simply a block of metal). Heat is conducted from the processor and can than dissipate from the many surface edges of the heat sink. In computers aluminium is usually used as it is lightweight.
Fans are used to help disperse heat and are often attached to the heat sink.