Each member of your team will be able to view sessions in your team workspace by default, which allows them to comment on the session plans. However, you will need to grant your colleagues editor rights individually if you would like them to work collaboratively on the session with you.
Anyone who is added as a collaborator to a session receives email notifications when a session has been commented on, which is particularly useful when working collaboratively with your colleagues. (It’s possible for the user to turn this email notification off in their account settings)
The difference between team seats and a collaborator
You can find the list of your team members at your team admin page. The people you add here count towards your seat limit for your Team subscription
People you invite to collaborate on a specific session do not count towards your seat limit: the logic we use is that it is always only the owner/creator of a session who needs to have Pro/Team user rights in order to have collaborators on a session.
Therefore you (and also your team members) can invite anyone else to work on the sessions you create, while the session collaborators can simply use the free Basic plan. This allows them to access any sessions shared with them (but they won’t be able to share their own sessions unless they’re on the Pro or Team plan).