You can view an overview of a repository's activity through Pulse. Pulse includes a list of open and merged pull requests, open and closed issues, and a graph showing the commit activity for the top 15 users who committed to the default branch of the project in the selected time period.
Commit co-authors are included in the commit activity summary if their commits were merged into the repository's default branch and they're in the top 15 users who have contributed the most commits.
If you want to see a detailed history of changes to a repository, you can use the activity view. The activity view displays all pushes, merges, force pushes, and branch changes, and associates these changes with commits and authenticated users. For more information, see "Using the activity view to see changes to a repository."
On GitHub.com, navigate to the main page of the repository.
Under your repository name, click Insights.
Optionally, to choose a different time period, select the Period dropdown menu in the upper-right corner of the Pulse overview. By default, Pulse shows the last seven days of repository activity.