ACTV is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "Change Pointer for Cost Center/Activity Type or Price" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_ACTV TYPE ACTV.
The ACTV table consists of various fields, each holding specific information or linking keys about Change Pointer for Cost Center/Activity Type or Price data available in SAP. These include GJAHR (Fiscal Year), LEDNR (Ledger for Controlling objects), VERSN (Version), VRGNG (CO Business Transaction)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .