CS6 perpetual pay one once you will get no update, there are some bugs. CS6 is what CS6 is bugs are not being fixed.. CC pay monthly for as long as you want Photoshop you will get new updates, new features and new bugs. Photoshop is a standalone product. CC does require occasional sign in to you Adobe Account to keep CC activated. CS6 does require connecting to Adobe for activation. When Photoshop is activated no internet connection is required. It run on your machine and need nothing external from you machine. .