In computer science, primitive types, the opposite of composite types, are datatypes with which valuess have a one-to-one correspondence to data objects stored in computer memory. They are also known as built-in types or basic types.

Typical primitive types are:

Operations on primitive types are fastest; integer addition, for example, is nothing but addition at the machine level.

Most programming languages, even object-oriented programming languages, do not allow extending primitive types, partly because such extension makes little sense but mainly because it is hard to implement such function without sacrificing the simplicity and efficiency. Composite types may be created using primitive types and/or other composite types.