How many types of actions in qtp

Reusable action: An action that can be called multiple times by the test with which it is stored (the local test), as well as by other tests.

Non-reusable action: An action that can be called only in the test with which it is stored, and can be called only once.

External action: A reusable action stored with another test. External actions are read-only in the calling test, but you can choose to use a local, editable copy of the Data Table information for the external action.