I don't think it can be covered in a general way, everyone's traumas are unique. Sometimes it involves going into the memory, reexperiencing parts of it (which can be a very visceral experience under the effects) from an objective place, really feeling them and letting go, forgiving, etc. It's usually more complicated than that- there are a lot of "hooks" that are created (relationships, places, the emotions felt going in/after an event). The most common traumas (sexual) create some downright awful patterns especially if it happened as a child (e.g. a parent who is supposed to be protecting you and providing safety...but is also doing bad things to you. There's a lot to undo there). It's usually not something taken care of in a single ceremony or even a weekend of ceremonies especially without a skilled practitioner.

Is there a difference between this and doing it another way? Hard to say. If the process resonates with you I think it can be done a lot faster and more completely this way. Some people can make little to no progress in therapy for years, dancing around the issue and constantly hitting defense mechanisms (often the memories of these things are blocked out and very hard to access under normal circumstances). A strong ayahuasca experience will put it front and center so you have no other choice than to deal with it. It's not easy, not some magic pill, and takes courage and willingness to go into it head on and do the work. It's absolutely not for everyone. I really love this modality so probably a bit biased- like asking a heart surgeon to heal your broken leg might get you a couple stents installed ;) it's very versatile but not always the best option.