The basic data structure used in programs is a number.C provides for two types of numbers - integers and floating point.Computer operations that involve text (characters,words or strings)still manipulate numbers.
Each data item used by a program must have a data type.The basic data types provided by C are shown in Table 1.Each type represents a different kind of number.you mast choose an appropriate type for the kind off number you need in the variable declaration section of the program