Ok, so the series is 26 poses. It is the same 26 poses every time. It is SUPPOSED to be done in a room heated to 105 degrees 40% humidity, but YMMV. Some studios have problems maintaining humidity so they make it hotter, and vice versa. The hardest studio is Vegas, they have ridiculous humidity in there.
It used to be 26 poses, each done twice, 90 minutes, but the past few years studios are adding 60 minute classes, which is essentially the same 90 minute class without all the rests in between the poses (some studios will remove the second round of a few of the poses as well).
It is a completely unique series, and each pose has a purpose - warmup, balancing series, back strengthening series, etc. Some poses are similar to other forms of yoga - trikonasana/triangle pose, for example, but it’s done a bit differently. The way to do each pose is very specific, but no one expects you do to anything exactly the way it’s supposed to be done - its all about just trying your best, and for the first few classes, just staying in the room, even if you spend the whole class laying down.
For more info:
https://www.bikramyoga.com/
The actual poses:
https://www.bikramyoga.com/about/26-postures/
Very interesting. I knew that you had been doing it a long time, and I really appreciate your concise explantation. thank you