Backing up and clearing space on my macbook.
hello, I just bought a Seagate Backup Plus (Slim) to allow me to backup my macbook Air, as well as to serve as a storage device so I can free up space on my Macbook. Can I use this device for both purposes? Also Time Machine is prompting me to erase the disc which worries me as I don't want to wipe off the start up information it comes with. I have a feeling I need to reformat the device before I can use it for both purposes?
Thankyou so much for any advice offered, very grateful.
Celia
MacBook Air 13", OS X 10.11