This means that variables can be used to describe different data types without the need to redefine the variable. Covered in depth is the concept of base types and complex data types are introduced. Operators are the simplest functional units in programming language. Combined with variables, operators allow the first useful programs to be developed. The use of operators with the corresponding data types is an important concept to understand.
Data typing allows the classification of data according to format and functional properties.
On a broad conceptual level, two basic data-types might be numbers and letters. Each has very different operational roles - numbers providing the capability to tally objects and letters providing access to language that describes an object. One useful classification of programming languages deals with their handling of variables and typing. The two broadest classes are dynamically typed and statically typed languages. A data type must be assigned when a variable is defined in a statically typed language.