Teams is a collaboration application which allows you and your colleagues to stay informed, organized and connected. It is easy to create a Team and invite members. A team help coordinate work for a department, committee, or a project. Teams provide the ability to share files, host discussions, manage projects (i.e., Planner), coordinate activities (i.e., Calendar), chat with team members and hold virtual meetings. Channels allow you to create work areas within a team, like sub-committees or topics.
A good overview video of Teams is at What is Microsoft Teams? - Microsoft Support.
More information on Teams can be found at Overview of teams and channels in Microsoft Teams - Microsoft Teams | Microsoft Learn