Introducing the Main Data type Groups : Introduction « PL SQL Data Types « Oracle PL/SQL Tutorial

There are four main groups:

1. Scalar datatypes represent single values that can't be divided into parts.
2. Composite datatypes include internal components that can be manipulated independently.
3. %ROWTYPE is an example of the PL/SQL RECORD datatype.
4. References contain pointers to other program items.
5. Large objects store or point to large amounts of textual or binary information, such as images, movies, or books.

Scalar datatypes are divided into families:

1. Numeric datatypes.
2. Character datatypes.
3. Date/time datatypes.
4. Boolean datatypes.