Execution log can be found in Setup -> Logs -> 'Execution log' tab and contains all execution session.
An execution session is created in response to a triggering event:
a Workflow is triggered,
a Button is pressed,
a Schedule executes,
a Form's button is pressed,
or a Form's field generates an event with a defined handler.
Note. An automation scenario that involves a Form, may spawn multiple execution sessions, one for a Button that brought up the Form, and one per each triggering event on the Form.
Inside an execution session's log entry you'll find the list of actions executed within the session.