How to view user activity and changes made by them

Admin Log

The admin log reports all changes made by administrators in admin tools. The log provides a gateway to user-defined reports from any of the three logs. You can search for events matching your selected criteria over a specified date range.

Usage and Access Log

The Usage and Access Log lets you evaluate report usage at the user account level.

Report Suite Change Log

The Report Suite Change log displays changes made to your report suites outside of admin.

Tools that can modify a report suite from outside the Admin Tools include:

• SAINT uploads made in a web browser (SAINT uploads made via FTP are not included in the change log)
• Changes made in earlier versions.
• Changes made by an account representative or Customer Care using internal tools

Reference: https://marketing.adobe.com/resources/help/en_US/reference/logs.html