What is meant by data types

Answer 1

A data type in a programming language is a set of data with values having predefined characteristics. Examples of data types are: integer, floating point unit number, character, string, and pointer. Usually, a limited number of such data types come built into a language. The language usually specifies the range of values for a given data type, how the values are processed by the computer, and how they are stored.

Answer 2

Used when variable is defined.
e.g. int number;
"int " is one of data type
and "number" is variable

Answer 3

simple and fast is the type of data you want to store or used for example storing numbers you have int data type.