A user-defined type is a data type that is defined to the database using a CREATE statement. A distinct type is a user-defined type that shares its internal representation with a built-in data type (its source type), but is considered to be a separate and incompatible data type for most operations. A distinct type is created with an SQL CREATE DISTINCT TYPE statement. A distinct type can be used to define a column of a table, or a parameter of a routine. For more information, see CREATE DISTINCT TYPE and User-defined types.