Science GPA question

Hi, I was reading on the medical school website that i want to apply to that their Science GPA was 3.62 and overall GPA was 3.65 -my question is this, how do they calculate your science GPA ? and your overall GPA?, im confused I assumed that whatever GPA you graduate with was your only one. Also does taking science courses at a CC calculate into a science GPA?

When you submit your application to the centralized service, you will type in every course you’ve ever taken as well as the grade (then verified with your transcripts). The centralized service (MD or DO) will then look through the courses and compile a variety of GPAs including overall, science, post-bacc.