You may need hardware, such as network interface adapters—generally network interface cards (NICs)—and cables, to physically connect your computers together into a network, but software is also an important component. This chapter examines the various software elements that provide network connectivity, including operating systems, clients, and directory services. These components provide the protocols that make up the networking stack, as well as the applications that make use of the network. Although you may be intimately familiar with some of the components discussed in this chapter, there are probably others that you have never used and should become familiar with.
This chapter assumes a basic knowledge of the networking concepts discussed in Chapter 1, "Networking Basics," and particularly an understanding of the layers of the Open Systems Interconnection (OSI) reference model, as covered in Lesson 2: The OSI Reference Model, in Chapter 1.