The history can be filtered to show you events relating to Media being access from different parts of your system. The history window can be toggled open or closed from the eye menu on the right-hand side.
Dispatch:
Results will be filtered to show only events where Media was checked out or in via the Dispatch window.
If the Media Order module is licensed, this filter will display all movements related to the creation of a Media Order for this Entry. See more details in the Media Order Manual.
Web Client:
This relates to a legacy feature and can be ignored.