Masters swim class vs regular swim class

Hello, I have read all the Masters Swimming 101 articles and I am still not sure what it means to be in a masters swimming class and how it is different from a regular advanced swim class. I am able to swim a lap (50 m) without stopping, freestyle and *** stroke. And I swim mainly to work out. I'm looking for someone to help me improve my form and swim more efficiently. It would be nice to participate in some of those swim competitions at some point, but I know I am nowhere close to being ready for that. My gym offers a Masters Swim class in the mornings. I am usually there during that time, and I've never seen anybody providing any coaching. I just see a bunch of people come in at that time and start swimming on their own. I've tried to ask the gym's swim department for more details, but they have been very vague. They say Masters Swim Class is more coaching whereas their adult swim class is for learning. Can someone describe what typically happens during a masters swim class? Should it the class be a re-occurring class or is it a one time clinic type of session? Should a coach be physically present or do you just get instructions to do on your own? Thanks!