Integer data type allows a variable to store numeric values. The storage size of int data type is 2 or 4 or 8 byte. It varies depend upon the processor in the CPU.
Character data type allows a variable to store only one character. Storage size of character data type is 1.
Float data type allows a variable to store decimal values. Storage size of float data type is 4. This also varies depend upon the processor in the CP.
Double data type is also same as float data type which allows up-to 10 digits after decimal.