It depends on our requirement. When we are required an integer to be stored in 1
byte (means less than or equal to 255) we use short int, for 2 bytes we use int,
for 8 bytes we use long int.
A char is for 1-byte integers, a short is for 2-byte integers, an int is generally
a 2-byte or 4-byte integer (though not necessarily), a long is a 4-byte integer,
and a long long is a 8-byte integer.