Team Drives are folders in Google Drive where files are owned by the drive rather than individual users. Everyone who is a member of a Team Drive can see and access the files so you can work together without having to share every file individually.
Each department has a team drive set up for them which can be used to store teaching resources that everyone in the department has access to.
Because all the files are accessible to all members of the department, you should think carefully about what you store in your department Team Drive.
Don't store private or confidential documents in Team Drives if you are not sure that everyone in that drive should be able to see it.
An example of what shouldn't be stored is appraisals. Line managers should store appraisals in their My Drive and then share it with the individual to whom it is applicable.