The first section details the authors time in Auschwitz, which of course was hard going and fascinating.
The second section is a more detailed explanation of his type of psychotherapy called Logotherapy. It is about how people can suffer any type of hardship as long as they perceive there to be some meaning to their life. It seemed to be rooted in stoicism, but I know nothing about psychotherapy so I’m not sure I grasp the details clearly.
There was a section at the end about “paradoxical intention” which was talking about an approach to get over hangups. For instance if you can’t sleep, stop trying so hard. It felt pretty out of place to be honest.
Wikipedia says there is some controversy about the book, how he is misleading about how much time he spent in Auschwitz, how he was really in another camp. I don’t really get the issue. It also says that he came up with Logotherapy before being in Auschwitz, rather than during but I thought that was clear in the text. I don’t think either of these points are gotchas, and I’m suspicious of the reason they’re prominently raised.