Within a team you can create a Space, this space is where you upload your files. All Spaces begin as a Personal Space. This means only your account can view the files within. Personal spaces can exist across multiple devices, but they are still only viewable from your account.
A Shared Space is the next step and is what you would use in a team collaboration environment. As soon as you invite another user into your Personal Space it turns into a Shared Space. Any files uploaded to a Shared Space can be downloaded by any member of the Shared Space. Other users can also upload files to this Shared Space.