The History tab is added to the Version Control tool window Alt+9 on invoking the Show History or Show History for Selection action. A new tab is created for each file or directory with the following name: History: <file_name>. The set of toolbar buttons differs slightly depending on your version control system.
The star next to a commit marks commits where the author and the user who committed the changes are different.
Tooltip and Shortcut
Click this button to refresh the current information.
Click this button to compare the selected revision of a file with its previous revision in the Differences Viewer.
Show All Affected Files
Click this button to open the Paths Affected in Revision dialog where you can view all files that were modified in the selected revision.
Show All Branches
Click this button to display changes from branches other than the current one.
Click to choose the amount of information you want to see in the History view. You can also select the Show Commit Timestamp option if you want PyCharm to show the commit timestamp instead of the time when a change was authored.
Click this button to show the commit message for the selected revision.
Open in GitHub
Click this button to open the page that corresponds to the selected commit on GitHub.