Kinda yeah... So, there are 7 Stages of Current, and 7 Classes which are something different.
Stages are determined by how well the user knows/believes in themselves and what they are capable of, which equates to the power of their.
At Stage 1 you are technically not a Current user, but have a limited amount of current in your being that you can use, this is achievable if a Current user has granted you use of Current or if a person who's ability is stealing powers does it on a Current user. Stage 1 only allows temporary use of weaker current abilities and cannot progress you up to Stage 2 without very frequent exposure over a long period of time.
Stage 2 is when you actually start generating your own Current energy, you are still very weak because you don't know the extend of what you can do you.
Stage 3 is when the Current user starts to understand a little more about their power and begins to generate it more rapidly and gain access to most of their abilities, in moments of great desperation a stage 2 or 3 Current user can temporarily boost their power to that of a higher stage.
Stage 4 is when the Current user gains full confidence in themselves and masters their soul and abilities. Nolan and Colt are somewhere around Stages 3 or 4.
Stage 5 is when things get really crazy, this is when the Current user realizes that they are completely unstoppable if they so desire, messing reality in large ways like freezing time or pulling souls from the afterlife, creating and reshaping matter in perfect ways.
Now Stage 6 is only theoretical, no known Current user has or likely ever will go past Stage 5, but it's said Stage 6 has the capabilities to reconstruct or destroy the world as we know it.
Stage 7 is the peak of power, once again theoretical, it's said a hypothetical Stage 7 would be well past that of universe creators, being on par with the meta world that exists outside our own.