User contributions pages list the edits that a particular user has made on a specific community. They allow you to see what edits others have made as well as keep track of your own edits.
Step by step
User contributions page
The user masthead lists a user's total edit count on this specific community
This tab gives you access to the users contributions
Here you can filter the user's contributions by namespace and date
This lists all the user's edits and allows you to link to the page and diff
Additional ways to access contributions pages
All contributions pages are in the form Special:Contributions/USERNAME, enabling easy linking. For example, Special:Contributions/FANDOM.
If the editor is not logged in, the IP address is used in place of the username. For quick access you can click on the IP address in Recent Changes or Page History.
By default the list is ordered by your most recent edits, but you can also sort it by community name or number of edits. It also lists important user groups you are in.