In today's world, everyone should be thinking deeply about issues of identity. Gender identity, national identity, identifying with a group, etc. And anyone who thinks deeply about issues of identity needs to read this book.

The book is set in the far future, and it has all the kinds of technology you'd expect, but it's all downplayed and in the background. No science details are discussed. That seems to put it into the "Space Opera" category of science fiction.