Very detailed and step-by-step; especially useful for everyone who starts to learn calculus be it from basic or from rather rigorous point of view. The appendix contains proofs of some of the most important theorems in basic calculus concept like squeeze theorem, making the text not lacking the needed rigour for fuller insight of the topic.
For those who wishes to learn advanced calculus, however, perhaps there is a need to peruse another text because in a way this text is not very close to real analysis; it is a broad text in terms of topic but the depth is not that much, though it does make an effort by not eliminating crucial proofs and explanations.
However, as far as calculus for the purposes of beginner analysis and engineering purposes are concerned, this book is more than enough - in fact, working engineers may still find this book quite useful. It is very readable, at least except chapter 15 and 16 when multiple integration is involved. I will have to reread chapter 15 and 16 a few times in future if I were to consider saying I have mastered the book.