Chapter Summary

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The following points summarize the key concepts in this chapter:

What Is a Network?

• The primary reasons for networking are to share information, to share hardware and software (reducing cost), and to centralize administration and support.
• A local area network (LAN) is the smallest form of a network and is the building block for larger networks.
• A wide area network (WAN) is a collection of LANs and has no geographical limitation.

Network Configuration

• Networks are classified into two principal groups based on how they share information: peer-to-peer networks and server-based networks.
• In a peer-to-peer network, all computers are equal. They can either share their resources or use resources on other computers.
• In a server-based network, one or more computers act as servers and provide the resources to the network. The other computers are the clients and use the resources provided by the server.
• Features of the two major network types are summarized as follows:

Comparison of Network Types

Consideration	Peer-to-Peer Network	Server-Based Network
Size	Good for 10 or fewer computers	Limited only by server and network hardware
Security	Security established by the user of each computer	Extensive and consistent resource and user security
Administration	Individual users responsible for their own administration; no full-time administrator necessary	Centrally located for network control; requires at least one knowledgeable administrator

Network Topology

• The physical layout of computers on a network is called a topology. Topologies can be physical (actual wiring) or logical (the way they work). There are four primary topologies: star, bus, ring, and mesh.
• In a bus topology, the computers are connected in a linear fashion on a single cable. Bus topologies require a terminator on each end of the cable.
• In a star topology, the computers are connected to a centralized hub.
• In a mesh topology, all computers in the network are connected to one another with separate cables.
• In a token-ring topology, the computers are connected physically in a star shape, but logically in a ring or circle. The data is passed from one computer to another around the circle.
• Hubs are used to centralize the data traffic and localize failures. If one cable breaks, it will not shut down the entire network.