Note the sub-title: this book consists of four lectures about Dirac, his work and developments from it in physics and mathematics, plus Hawking's laughably ignorant memorial address. (He repeatedly insulted his hosts for delaying for 11 years an event that was, in fact, only one year beyond the minimum requirement of ten years post Dirac's death.)
Only the first lecture is really biographical and even that takes time out to discuss Dirac's scientific contributions. From there the book gets progressively more technically challenging, ending with a lecture on the Dirac operator and spinors that in detail is going to be incomprehensible to anyone without an advanced working knowledge of topology. (The gist is that we have no clue what spinors mean, geometrically, in the way we know what vectors and tensors are, for example.)
In between, there's good stuff on antimatter from prediction to present day understanding and similarly Dirac's magnetic monopoles then to now.
Much of this book will go over the heads of the casual reader and if you want anything more than a cursory biography, you will also need to look elsewhere, but for physicists, it's a worthwhile publication.