TCP/IP is the basis for almost all of the communication we will discuss in this book. Because it is the most widely used network protocol, we will focus on it.
Hypertext Transfer Protocol (HTTP, RFC 2616) is the server/client-based protocol used to transfer web pages across a network. A simple HTTP transaction is a good example of TCP/IP communication. Every time you search the Internet with Google, check the weather, or even check your fantasy sports teams, you are transferring data via TCP/IP using HTTP.
The TCP/IP protocol is really a stack of protocols, consisting of several different protocols on both Layers 3 and 4 of the OSI model. These protocols include TCP, IP, ARP, DHCP, ICMP, and many others.