| Term | Definition |
| typedef existing_type new_type_name ; | defined data type format |
| defined data type | allows the definition of our own types based on existing data types |
| union | allow one same portion of memory to be accessed as different data types |
| struct structure_name {member_type1 member_name1; member_type2 member_name2...} object_names; | declaration of a union |
| anonymous union | union without a name |
| enum enumeration_name {value1, value2,...} object_names; | declaration of an enumeration |
| enumeration | creates new data types to contain something different that is not limited to the values fundamental data types my take |