Pull together a team.
Use chat instead of email.
Securely edit files at the same time.
See likes, @mentions, and replies with just a single tap.
Customize it by adding notes, web sites, and apps.
https://support.microsoft.com/en-us/office/sign-in-and-get-started-with-teams-6723dc43-dbc0-46e6-af49-8a2d1c5cb937
https://support.microsoft.com/en-us/office/set-up-your-teams-mobile-apps-1ba8dce3-1122-47f4-8db6-00a4f93117e8