With Microsoft Teams on your PC, Mac, or mobile device, you can:

• 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.

Learn more at Microsoft's site.

Copied from: https://support.microsoft.com/en-us/office/video-what-is-microsoft-teams-422bf3aa-9ae8-46f1-83a2-e65720e1a34d