The book is a collection of essays Stephen Hawking wrote and came out after his death. The insight he gives is very digestible, not only because of his charming style to write. Its fair to say that the book is a good introduction to Stephen Hawking's work and the field he worked in, not only suited for absolute newcomers to cosmology and astronomy but also those who have gathered a fair share of knowledge about said fields.But don't expect complicated equations and the explanation of those, the main purpose of this book is to spark interest, giving enough information to build some knowledge but not getting boring or technical. Thereby there is no specific audience the book is aimed at, everyone could read and understand it easily, but keep in mind that some facts stated are simplified to make them more digestible and astrophysics are a lot more broad than the book could ever depict.
I found some chapters more interesting than others, preferring the ones in which he discusses several ideas and how things could have been. I also must say that the chapter "Is there a God" didn't speak a lot to me, but was saved by his exploration of what God could be in terms of physics.
Its a light work to read, so most definitely worth it.