About Atom Tables

The system provides a number of atom tables. Each atom table serves a different purpose. For example, dynamic data exchange (DDE) applications use the global atom table to share item-name and topic-name strings with other applications. Rather than passing actual strings, a DDE application passes global atoms to its partner application. The partner uses the atoms to obtain the strings from the atom table.

Applications can use local atom tables to store their own item-name associations.

The system uses atom tables that are not directly accessible to applications. However, the application uses these atoms when calling the Win32 application programming interface (API). For example, registered clipboard formats are stored in an internal atom table used by the system. An application adds atoms to this atom table using the RegisterClipboardFormat function. Also, registered classes are stored in an internal atom table used by the system. An application adds atoms to this atom table using the RegisterClass or RegisterClassEx function.