I find the book also provides good and clear definitions of its topics. Initially I read it from cover to cover, and came out with a clearer understanding of the web as a whole. It provides an excellent overview for anyone who has studied some of the parts, such as HTML pages and CGI scripts, and wants to understand how they relate.
The back cover says "This is a book that anyone who does serious work on the Web will find indispensible." I wholeheartedly agree.