Teams - Files

Files that you share in a channel are stored in your team's SharePoint folder, which is found in the Files tab at the top of each channel.

Files that you share in a private or group chat are stored in your OneDrive for Business folder, which is found in the Files tab at the top of a chat.

Teams - First things to know about files in Microsoft Teams

How To

Teams - How to share a file with Teams

Teams - Version control of file

Teams - How to Sync teams files to your computer

Teams - Recovering deleted files