wirelessly. Marge also connects her iPad to the network wirelessly.
You can also see in the figure that Homer’s computer has a printer attached to it. Because of the network, Bart, Lisa, and Marge can also use this printer.
Finally, you can see that the entire network is connected to the Internet via the router.
FIGURE 1-1: A typical network.
Computer networking has its own strange vocabulary. Although you don’t have to know every esoteric networking term, it helps to be acquainted with a few of the basic buzzwords:
LAN: Networks are often called LANs, short for local area network. In Figure 1-1, the LAN consists of the home router and the computers and iPad that are connected to it directly via cable or wirelessly. LAN is the first TLA — or three-letter acronym — of this book. You don’t really need to remember it or any of the many TLAs that follow. In fact, the only three-letter acronym you need to remember is TLA. You might guess that the acronym for four-letter acronym is FLA. Wrong! A four-letter acronym is an ETLA, which stands for extended three-letter acronym. After all, it just wouldn’t be right if the acronym for four-letter acronym had only three letters.
WAN: The second TLA in this book is WAN. The WAN is part of the network that connects to the Internet. WAN stands for wide area network. Okay, fine. Technically, WAN is the third TLA. The first TLA was LAN, and the second TLA was TLA. So that makes WAN the third TLA.
On the network: Every computer connected to the network is said to be “on the network.” The technical term (which you can forget) for a computer that’s on the network is a node. Another term that’s commonly used to mean the same thing is endpoint.
Online, offline: When a computer is turned on and can access the network, the computer is online. When a computer can’t access the network, it’s offline. A computer can be offline for several reasons. The computer can be turned off, the user may have disabled the network connection, the computer may be broken, the cable that connects it to the network can be unplugged, or a wad of gum can be jammed into the disk drive.
Up, down: When a computer is turned on and working properly, it’s up. When a computer is turned off, broken, or being serviced, it’s down. Turning off a computer is sometimes called taking it down. Turning it back on is sometimes called bringing it up.
Local, remote: A resource such as a disk drive is local if it resides in your computer. It’s remote if it resides in another computer somewhere else on your network.
Internet: The Internet is a huge amalgamation of computer networks strewn about the entire planet. Networking the computers in your home or office so that they can share information with one another and connecting your computer to the worldwide Internet are two separate but related tasks.
Why Bother with a Network?
Frankly, computer networks are a bit of a pain to set up. So why bother? Because the benefits of having a network outweigh the difficulties of setting up one.
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 four: files, resources, programs, and messages.
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 email 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 your friend 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 CD or DVD 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 printer attached to Homer’s computer in Figure 1-1 is a shared resource, which means that anyone on the network can use it. Without the network, Bart, Lisa, and Marge would have to buy their own 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 Bart wants to share a file with Lisa, and a shared hard drive has been set up on Homer’s computer. All Bart has to do is copy his file to the shared hard drive in Homer’s computer and tell Lisa where he put it. Then, when Lisa gets around to it, she can copy the file from Homer’s computer to her own.
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 files to a shared network location. Then you can use that copy to install a separate copy of the program on each user’s local hard drive.
The advantage of installing a program from a shared network drive is that you don’t have to download the software separately for each computer on which you want to install the software. 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 downloading and installing the program separately on each computer.)
