Eevee is used just to see the updates in real time right ?
No – Eevee is good enough to be used as a final render solution, especially when physical accuracy is less a priority. For example this entire animation was rendered with Eevee:
So Eevee has a lot of potential for stylized / cartoony stuff but it also can be used for realistic rendering as well.
so cycles can practically be used to render maybe a 30sec final animation right?
Unless you have a super-high end graphics card, you definitely will not be able to achieve 30-sec cloud renders with Cycles. The last lesson in this course I compare Eevee and Cycles render times and it’s not pretty 😅