Describe data classes? | SAP ABAP

it gives the information of table falls under which area (ie master data, transactional data , customizing data)
Master data: It is the data which is seldomly changed.(it is rarely updated and regularly changed).
EX. Vendor, customer, general ledger etc.
Transaction data: It is the data which is often changed(it is the data regularly updated and changed).
Ex: sales order, purchase order, delivery, invoice etc.
Control/customizing data: (Organization data): It is a customizing data which is entered in the system when the system is configured and is then rarely changed.
( System data):It is the data which R/3 system needs for itself.