These are fundamental data types in C namely integral( int and char ), floating-point( float and double ) and void .



char is used to store any single character, int is used to store integer value, float is used for storing single precision floating point number and double is used for storing double precision floating point number.



We can use type qualifiers with these basic types (int, char, float and double) except void to get some more types.



There are two types of type qualifiers:

Size qualifiers - short , long

Sign qualifiers - signed , unsigned



The qualifiers signed and unsigned can be applied to char and integer types. When the qualifier unsigned is used the number is always positive, and when signed is used number may be positive or negative. If the sign qualifier is not mentioned in integers, then by default signed qualifier is assumed. If the sign qualifier is not mentioned for char type, then whether the char type is signed or unsigned is machine dependent. The range of values for signed data types is less than that of unsigned type. This is because in signed type, the leftmost bit is used to represent the sign, while in unsigned type this bit is also used to represent the value.



The qualifier short and long can be applied to int type to get types short int and long int . The qualifier long can be applied to double to get the long double which stores extended precision floating point number.



