All the computer elements can be divided into two main categories – Hardware and Software. Hardware consists of all the computer elements which we can see and touch. Software consists of applications and programs used in computer.
When we specially talk about hardware it consists of all devices which make a computer. The devices which are commonly used as a part of computer hardware are :-

INPUT DEVICES :
1. Keyboard
2. Mouse
3. Microphone
4. Scanner
5. Web Camera
6. Joystick
7. Touch Screen

STORAGE DEVICES :
1. Hard Disk
2. CD
3. DVD
4. Floppy Disk
5. USB Flash Drive

OUTPUT DEVICES :
1. Monitor
2. Printer
3. Speakers


NETWORKING DEVICES :
1. Modem
2. Network Card
3. Hub

OHER DEVICES :
1. Processor
2. RAM
3. Power Supply