I would like to know which one is better to use.

Correct me if I am wrong Please and I welcome any sugestions.

If I use animation than I think it is more up to Graphic Card and if I use script than it is more up to CPU.

Simple example:
I have sphere and I want it to rotate - I can do it either by using animation or script.

Which one is way to go?

From my perspective using script gives me more freedom for adjustments.
I hope this question is easy enough to understand.

Whatever difference there might be isn’t going to be big enough to be noticeable. Use whatever is more convenient for the situation.