A computer network consists of two or more computing devices that are connected in order to share the components of your network (its resources) and the information you store there, as shown in Figure 1.1. The most basic computer network (which consists of just two connected computers) can expand and become more usable when additional computers join and add their resources to those being shared.
The first computer, yours, is commonly referred to as your local computer. It is more likely to be used as a location where you do work, a workstation, than as a storage or controlling location, a server. As more and more computers are connected to a network and share their resources, the network becomes a more powerful tool, because employees using a network with more information and more capability are able to accomplish more through those added computers or additional resources.
The real power of networking computers becomes apparent if you envision your own network growing and then connecting it with other distinct networks, enabling communication and resource sharing across both networks. That is, one network can be connected to another network and become a more powerful tool because of the greater resources. For example,
you could connect the network you and your classmates develop for this course to similarly constructed networks from other introductory networking classes if you wanted them to share your information and networked resources. Those classes could be within your own school, or they could be anywhere in the world. Wherever that newly joined network is, the communication and resource sharing activities in that new network could then be shared with anyone connected to your network. All you have to do is join that new network’s community or allow its members to join yours.
In addition, a company’s cost of doing business can be reduced as a result of sharing data (defined as a piece or pieces of information) and resources. Instead of having individual copies of the data at several locations around the company, and needing to keep all of them similarly updated, a company using a network can have just one shared copy of that data and share it, needing to keep only that one set of data updated. Furthermore, sharing networked resources (like printers) means that more people can use a particular resource and a wider variety of resources (like different printers) can be used by each network user. Any time a company can do more with less, or buy fewer items to do the same job, its total costs are reduced, and it is able to make more money per dollar spent.