What is a SERVER and a CLIENT?
The network computer that contains the hard drives, printers, and other resources that are shared with other network computers is a server. This term comes up repeatedly, so you have to remember it. Write it on the back of your left hand.
Any computer that's not a server is a client. You have to remember this term, too. Write it on the back of your right hand.
Only two kinds of computers are on a network: servers and clients. Look at your left hand and then look at your right hand. Don't wash your hands until you memorize these terms.
The distinction between servers and clients in a network has parallels in sociology-in effect, a sort of class distinction between the "haves" and "have-nots" of computer resources:
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Usually, the most powerful and expensive computers in a network are the servers. There's a good technical reason: Every user on the network shares the server's resources.
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The cheaper and less powerful computers in a network are the clients. Clients are the computers used by individual users for everyday work. Because clients' resources don't have to be shared, they don't have to be as fancy.
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Most networks have more clients than servers. For example, a network with ten clients can probably get by with one server.
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In many networks, a clean line of demarcation exists between servers and clients. In other words, a computer functions as either a server or a client, and not both. For the sake of an efficient network, a server can't become a client, nor can a client become a server.
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Other (usually smaller) networks can be more evenhanded by allowing any computer in the network to be a server and allowing any computer to be both server and client at the same time.
What a Network Can DO?
Why Network Plays an Important Role?
Frankly, computer networks are a bit of a pain to set up. So, why bother? Because the benefits of having a network make the pain of setting up one bearable. You don't have to be a PhD to understand the benefits of networking. In fact, you learned everything you need to know in kindergarten: Networks are all about sharing. Specifically, networks are about sharing three things: files, resources, and programs.
Sharing files
Networks enable you to share information with other computers on the network. Depending on how you set up your network, you can share files with your network friends in several different ways. You can send a file from your computer directly to a friend's computer by attaching the file to an e-mail message and then mailing it. Or, you can let your friend access your computer over the network so that your friend can retrieve the file directly from your hard drive. Yet another method is to copy the file to a disk on another computer and then tell your friend where you put the file so that he can retrieve it later. One way or the other, the data travels to your friend's computer over the network cable, and not on a floppy disk, CD-RW, or flash drive, as it would in a sneakernet.
Sharing resources
You can set up certain computer resources-such as hard drives or printers-so that all computers on the network can access them. For example, the laser printer attached to Ward's computer in Figure 1-1 is a shared resource, which means that anyone on the network can use it. Without the network, June, Wally, and the Beaver would have to buy their own laser printers.
Hard drives can be shared resources, too. In fact, you must set up a hard drive as a shared resource to share files with other users. Suppose that Wally wants to share a file with the Beaver, and a shared hard drive has been set up on June's computer. All Wally has to do is copy his file to the shared hard drive in June's computer and tell the Beaver where he put it. Then when the Beaver gets around to it, he can copy the file from June's computer to his own (unless, of course, Eddie Haskell deletes the file first).
Tip | You can share other resources, too, such as an Internet connection. In fact, sharing an Internet connection is one of the main reasons many networks are set up. |
Sharing programs
Rather than keep separate copies of programs on each person's computer, putting programs on a drive that everyone shares is sometimes best. For example, if ten computer users all use a particular program, you can purchase and install ten copies of the program-one for each computer. Or, you can purchase a ten-user license for the program and then install just one copy of the program on a shared drive. Each of the ten users can then access the program from the shared hard drive.
In most cases, however, running a shared copy of a program over the network is unacceptably slow. A more common way of using a network to share programs is to copy the program's installation disks or CDs to a shared network drive. Then you can use that copy to install a separate copy of the program on each user's local hard drive. For example, Microsoft Office enables you to do this if you purchase a license from Microsoft for each computer on which you install Office.
The advantage of installing Office from a shared network drive is that you don't have to lug around the installation disks or CDs to each user's computer. And, the system administrator can customize the network installation so that the software is installed the same way on each user's computer. (However, these benefits are significant only for larger networks. If your network has fewer than about ten computers, you're probably better off installing the program separately on each computer directly from the installation disks or CDs.)
How to Setup a Server
One of the basic choices that you must make before you proceed any further in building your network is to decide which network operating system (NOS) to use as the foundation for your network. This chapter begins with a description of several important features found in all network operating systems. Next, it provides an overview of the advantages and disadvantages of the most popular network operating systems.
Of course, your work doesn't end with the selection of an NOS. You must then install and configure the NOS to get it working. This chapter provides an overview of what's involved with installing and configuring the most popular NOS choice, Windows Server 2003.
Network Operating System Features
All network operating systems must provide certain core functions, such as connecting to other computers on the network, sharing files and other resources, and providing for security. In the following sections, I describe some core NOS features in general terms
Network support
File-sharing services
Multitasking
Directory services
Security services