whats the difference between photoshop and photoshop cc?

"Photoshop CC" is the designation for subscription-based versions of Photoshop later than CS6. CS6 and earlier versions were licensed outright (the so-called "perpetual license" model). Creative Cloud versions are downloaded as part of an Adobe Creative Cloud subscription either for the single app and various extras ($10/month) or as part of the more expensive full Creative Cloud subscription. Go to https://www.adobe.com/creativecloud/photography.html#photography-mini-plans for the details.