The full form of COMPUTER is Common Operating Machine Particularly used for Technological Engineering Research.

Computer- computer is a machine
The  full form of computer is just below:
C-Commonly
O-Operated
M-Machine
P-Particularly
U-Used for
T-Technology
E-Education and
R-Research
Computer is a electronic device which helps for arithmetic and logical calculations.
Computer is particularly contains arithmatic and logical unit i.e ALU.this electronic machine contains memory also. Which helps to store data.computers can be digital ,analog and hybrid based on technology.
There are some other computers also Super computer, personal computer, desktops, laptops,  etc.
Computer is also consider as a programming machine because it cannot do anything without program. It takes raw data from user as a input process it and produces output to user.