A shared folder is a folder on your school's server, in which you and everyone from your school may save and/or view files. You would normally save to this folder if you wish for others in your building to be able to also see the file.
The Shared folder is on your S: drive. To access it, open My Computer. Then open the S: drive. Student do not have network permissions to open or save to the shared folders on the S: driive.