The global address book normalizes the name and address data held against entities such as customers and suppliers. Changing the name, address, or contact information against a customer will also appear to change the address of the vendor if it is linked to the same address book entry and this information isn't actually stored in the vendor record.
It does so by associating the entity with a record in
DirPartyTable. This table also has some special case tables that inherit from it, as shown in the following diagram (which was taken using the Type hierarchy browser):
The tables generally used are