Computer Hardware Parts:
System Unit

The system unit is the heart of a computer system. Generally, it’s a
rectangular box placed on or beneath your desk. There are several
electronic components which process information inside this box. The
most vital of these components is the central processing unit (CPU), or
microprocessor, which acts as the brain of your computer. Another
component is the RAM or the random access memory which temporarily
stores data that the CPU uses while the computer is on. When the
computer is turned off, the information stored in RAM gets erased.

Hard Disk Drive

Your computer’s hard disk drive stores data on a hard disk, a firm
plate or stack of plates with a magnetic surface. The hard disks
normally serve as your computer’s primary means of storage, holding
almost all of your programs and files as it can hold enormous amounts of
information. The hard disk is usually located inside the system unit.

DVD and CD Drives

Almost all computers today come equipped with a DVD or CD drive,
generally located on the front of the system unit. CD drives use lasers
to read or retrieve data from a CD and several CD drives could also
write or record data onto CDs. DVD drives could do everything that CD
drives can plus they can also read DVDs. If you have a DVD drive, you
could watch movies on your computer. Several DVD drives could record
data onto blank DVDs.

Floppy Disk Drive
Floppy disk drives
store information on floppy disks, also known as floppies or diskettes.
Floppy disks compared to CDs and DVDs can store only a small amount of
data. They also recover information more slowly and are more prone to
damage. For these reasons, floppy disk drives are less admired than they
used to be, though some computers still include them.