This document contains figures and content from Chapter 25 of the book "TCP/IP Protocol Suite: Part 2, Application Layer" published by McGraw-Hill in 2001. The chapter covers various topics related to application layer protocols in TCP/IP including DNS, FTP, SMTP, SNMP, HTTP, and HTML. There are over 30 figures illustrating concepts, components, messages, and document types for these different application layer protocols that operate over the Internet.