In your Feed you can view your missed calls, meeting request, unread messages, and more.
Instant Message your colleagues by looking through your suggested contacts, or select the "New Chat" icon to search though your contacts, or external users via email. It must be noted that you will only be able to message external email addresses if they have the right Office 365 Licence and their IT has allowed external messages.
Create and use Channels to collaborate on files, engage in text based chat with your colleagues and host meetings with these groups.
Your Teams calendar is synced with Outlook, so your entries are the same on both. You can use the calendar to schedule meetings with individuals or your Teams.
If this feature has been enabled, you can use Teams as a phone
You can view the most recent files that you have shared and files you have downloaded recently through Teams. You can also use Files to connect to your Cloud storage, such as Microsoft's own OneDrive or others like Google Drive and Dropbox.