Data types are specifications provided with the variable or function name. These data type are categorized into three types as follows.
1.    Primary or fundamental data types
2.    Derived data type
3.    User defined data type

The following are the most commonly used primary data type:

Character data type is used to store single character or number at a time. The memory space requirement for character type of data is 8 byte for 16 bit machine.
Integer allows to store integer values only. No decimal points are allowed. Integer takes 16 bytes of memory to store the integer value on 16 bit machine.
Float types stores only floating point values. The values should be with the decimal places. Float takes 32 bytes of memory to store floating value on 16 bit machine.
Double type stores the double value than float. Double takes 64 bytes of memory to get store on 16 bit machine.