To collaborate on files within Microsoft Teams, you can work on them together in real-time by opening the document directly within a channel. For even quicker access, you can turn any file into a tab at the top of a channel, making it immediately visible to everyone. All shared documents are automatically organized in the "Files" tab, where you can upload new files and folders or pin the most important ones to the top for easy access. To share a file with a teammate, simply select "copy link," set the appropriate permission level, and paste the link into a chat or channel conversation. This ensures everyone is working from the same version without creating confusing duplicates.