System Stream is the system's built-in stream that generates queries dynamically; to use System Stream, go to
Menu → Preferences → Streams and enable it.
Issues on GitHub where your team mentioned
Issues in the repositories you're watching on GitHub
Individually registered issues
Team Stream allows you to get the teams you belong to on GitHub and handle issues where they are mentioned. When you join a new team, the team will be added automatically.
Watching Stream can retrieve repositories that you have watched on GitHub and handle issues in those repositories. When you watch a new repository, it will automatically add it to your repository.
Subscription Stream provides the ability to handle individually registered issues. Register the URL of the issue from the
Subscription Stream menu.