The computer case is an enclosure made out of either plastic or metal that houses most of the components. The case in most cases is small enough to fit underneath a desk.Laptops are computers that usually come in a clamshell form factor, again however in more recent years deviations from this form factor have started to emerge such as laptops that have a detachable screen that become tablet computers in their own right.
A power supply unit (PSU) converts alternating current (AC) electric power to low-voltage DC power for the internal components of the computer. Laptops are capable of running from a built-in battery, normally for a period of hours.
The motherboard is the main component of a computer. It is a large rectangular board with integrated circuitry that connects the other parts of the computer including the CPU, the RAM, the disk drives(CD, DVD, hard disk, or any others) as well as any peripherals connected via the ports or the expansion slots. It is essentially the spine of the computer.
The CPU performs most of the calculations which enable a computer to function, and is sometimes referred to as the "brain" of the computer.
The random access memory stores the code and data that are being actively accessed by the CPU.