I am planning to do a skydiving course and I was thinking of doing the course in France. That means, I would get a stage PAC license course instead of AFF. I want to know how PAC is different from AFF (previously I have only heard of AFF) and can I use the PAC license to skydive anywhere in the world?
If you mean you are learning to skydive and will be taking PAC instead of AFF, then the differences are minor. IIRC, in PAC the last jump is number 8, whereas in AFF and PFF it's jump 7.
There's also the Canadian version, PFF, and I assume other variations as well. Generally, schools do not follow any of these exactly and add their own variations.