This is a great resource on fuzz testing algorithms & internals. I find myself coming back to it occasionally when building new fuzzing techniques at Fuzzbuzz.

Can't figure out what this is.

Can someone explain to me what type of fuzzing it covers and what the target audience is?

It's just below the fold:

Who this Book is for This work is designed as a textbook for a course in software testing; as supplementary material in a software testing or software engineering course; and as a resource for software developers. We cover random fuzzing, mutation-based fuzzing, grammar-based test generation, symbolic testing, and much more, illustrating all techniques with code examples that you can try out yourself.