Welcome to the Forum for the Structured Educational Program

You're not the only one who is confused by this, @berlinale! It is further confused by references in some places to Alan Gordon's original two-part "TMS Recovery Program" (on the tmswiki.org site) which is much shorter than his 21-day Pain Recovery Program (here on the forum). Both of these programs were generously donated by Alan Gordon LCSW, several years after the original Structured Education Program (the SEP) which is also on the main tmswiki.org site.

I have been indicating my bias towards the SEP for a long time, but that's primarily because it's the only program we had when I was experiencing my original TMS recovery in 2011. I have now finally read through the entire PRP, although I did not play most of the video or audio clips that are provided in each module. My impression for a long time has been that the PRP does not delve very deeply into the emotional work, and that is very definitely the case. There are no writing exercises. This appeals to many people! However, many of us believe (based on our own experiences) that developing an emotional writing skill is essential to true recovery unless you have the emotional ability to develop a significant mindfulness protocol that you can maintain on a regular basis. Most of us can't do that - but we can quickly go to our emotional writing skills when we experience setbacks. (BTW, this is most frequently referred to as Journaling, or if you follow Nicole Sachs, she calls it JournalSpeak).

All that being said, the PRP is a truly excellent, fairly short, and very easy-to-follow compendium of recovery techniques addressing all of the essential topics - check out the titles at the main page: Pain Recovery Program | TMS Forum (The Mindbody Syndrome) It is 21 modules, labeled "days" but honestly, you could do more than a day at a time - always with the caveat that you need time to let the information sink in, so don't do what I did and skim through it all in a couple of hours.
Here's what Alan says on the last day:

SO - I have no doubt that the knowledge and skills which can be obtained by doing the PRP are quite valuable. Just know that in the thirteen years I've been hanging out here, we also often see people who return with serious setbacks after recovering in the past - sometimes many years in the past - and it turns out that they really need to go deeper and really do "THE work". And the best free resource for doing "the work" is the SEP - the Structured Educational Program on the main tmswiki.org site.

I actually think you can probably do the PRP and the SEP side-by-side. For better or worse, there are no hard and fast rules (this is frustrating to many people, who desperately want clear guidelines!). Trust your own judgement as to how the "Days" match up with each other. You can take a break from one, and only do the other. The information presented in the SEP is quite different, perhaps more dense, and, after the first few modules, it asks for participation in writing exercises. We generally recommend that the SEP literally be done one Day at a time. Rushing through it is not effective.

If you experience an increase in symptoms while doing the SEP, go directly to Day 19 in the PRP and read about Extinction Bursts. Then keep going. That's the second most important thing, right after treating yourself with kindness and compassion.