Four Parts

The book is divided into four parts:

Part I, Structural: Linux, Apache, MySQL, Perl ”the structural system foundations on which LAMP is built and the other programs run.

Linux is the operating system this is all based on. We touch only lightly on Linux because it's a big subject and one that doesn't need to be dealt with much after it's installed.
Apache is the webserver software that serves web pages up to clients and decides how requests for documents, forms, and so on will be processed . Chapter 1 talks about the basics of configuring and setting up a web site.
MySQL is an SQL database program. It is "the world's most popular Open Source Database" (it says so on their web site).
Perl is the programming language of choice for interacting with text files, shell scripts, and a million other things. (Python is similar to Perl in functionality; however, we chose Perl for our purposes because we know it better and like it.)

Part II, Static: WML is a set of programs that facilitates building and managing large-scale static web sites using HTML files.

Part III, Dynamic: CGI and mod_perl are the programs with which to build dynamic web sites.

CGI is the tried-and-true way of generating dynamic content.
mod_perl is a better, faster, and stronger way of generating dynamic content; mod_perl combines two pillars of Open Source: Apache and Perl.

Part IV, Embedded: SSI, Embperl, Mason, and PHP are embedding programs to use within HTML pages.

Server Side Includes (SSI) is built into Apache. Its job is to preprocess HTML files, turning SSI directives into HTML text; it allows web programmers to embed executable code into HTML files.
Embperl and Mason are Perl modules for building embedded web content.
PHP is another way to embed executable code with HTML files. PHP does what Embperl and Mason do, just differently.

So why have so many choices? Read on, gentle reader, and you will discover that a myriad of choices is the Open Source way!