A data type is a classification of data, which can store specific type information. The types of data are used mainly in computer programming, in which variables are created to store data. Each variable is assigned a data type determines the type of data can contain the variable. The term "data type" and 'primitive data type "is often used interchangeably. Primitive data types are predefined types of data, are compatible with the programming language. For example, whole character, and the chain are all primitive data types. Developers can use these data types when creating variables in your programs. For example, a programmer can create a variable called "name" and define it as a string data. The variable then stores the data as a string characters.

Non-primitive data types are not defined by the programming language, but instead created by the programmer. They are sometimes called "Variables of reference" or "object references, they refer to a memory location that stores data. In the Java programming language, non-primitive data types are called "objects" because they are created, rather than predefined. While an object can contain any type of data, information referred to in the subject can still be stored as a primitive type data.