The alternative to sneakernet is a network consisting of physical links that connect two or more computers and related equipment. These links can use wires, radio signals, or a combination of both to move computer data (and any other information that can be converted to and from computer data) between any pair of network nodes.
Every computer connected to a network sends and receives data through a connector or radio antenna. Depending on the data transfer speed and the network's specific requirements, the computer might use a parallel port, a serial port, an Ethernet port, a USB or FireWire port, or a Wi-Fi antenna. Because these connectors and antennas move data in both directions, they are input/output ports or I/O ports, but that term is more often used to describe the computer's serial and parallel data connectors.
After you connect your computers together, you will discover that you can do many things through the network that you may not have expected. By the time you have lived with the network for a few weeks, you won't think much about it, but you'll use it all the time.
When you connect your computer to a network, you can allow other people to read and write files that are located on your computer's hard drives and other storage media, and you can open and store files from other computers. File sharing is one of the most common and the most convenient uses of a network.
File sharing has many uses: You can use it to collaborate with other people on a single document or other file, to play music or watch videos stored on another computer, and for just about everything else that you can do with your own files. In effect, every unprotected file stored on any network computer is as easy to use as a file on your own computer.
For example, Figure 1-1 shows a Windows display of disk drives and individual directories on a home network (other file-sharing methods also exist). You can open a file or folder on a remote computer by double-clicking an icon or a filename, just as you would on your own machine.
Of course, you probably have some files on your own computer that you don't want to share: personal letters, confidential financial records, medical information, and so forth. A well-designed file-sharing system allows each user to set every file or folder as either "public" or "private."
For more about sharing files with other computers on your home or office network, see Chapter 12.
When you order a connection to the Internet, the telephone company or the cable TV company installs just one connection point. It doesn't matter if the Internet service uses a dial-up telephone line, a high-speed DSL line, a cable TV service, a fiber optic link, or some kind of radio link; your Internet service terminates in just one place, most often in a piece of electronic equipment called a modem (that's geek-speak for modulator/demodulator, a device that converts between computer data and some other type of communications signal). If you have just one computer, you can connect it directly to the modem; but when you want to connect two or more computers to the Internet at the same time, you'll need a network.
For many families, a high-speed Internet connection provides the reason to start thinking about installing a home network. When you spend that extra money for a DSL or cable Internet link (or fiber optic link), you want easy access to the Internet from every computer in the house. When you connect your network to the modem through a gateway router (shown in Figure 1-2), you can reach the Internet through any computer on that network. Some modems require a separate router to distribute the Internet connection to multiple computers, while others have built-in routers.
Connecting your network to the Internet is not difficult, but it's easier with detailed instructions. You can find those instructions in Chapter 10.
Instant message programs display text on a distant computer's screen almost as fast as you can type them. They're useful for exchanging notes, asking questions, and nonspecific chatter within a business or between friends and family members. When a new message arrives, the messaging program pops up in a new window on the recipient's screen. If you attach a microphone and speaker to each computer, you can use a similar program to speak to the person at the distant computer rather than using the keyboard and screen. And if you add a camera at each end, you can use a video messaging system that allows each of you to see the other party during the conversation.
Within a home or small office network, you can use instant messaging, with or without sound and pictures, to communicate from one room to another. It might be a simple message, such as "Dinner's ready," or a more complicated request for information from someone else in the building. And of course, if there are young people in the house, the instant message program will quickly become a channel for gossip and idle conversation.
For more about instant messaging programs, see Chapter 16.
In most homes and small businesses, there's no need for every computer to have a printer available for its exclusive use, because nobody uses a printer all the time. It's often more practical to attach a single printer to a network (or maybe one for black-and-white pages and another for color) rather than buying a separate printer for each computer.
When you only need a single printer, you can often buy one that provides better images and faster performance for considerably less than the price of two or three cheaper models. The same kind of economy can also apply to a flatbed scanner and other specialized input or output devices.
A network printer can either connect directly to the network as a separate node (a printer server) or through one of the network's computers. Look for information about both types of printer connections in Chapter 14.
The same home network that carries data to computers can also distribute music, movies, and other audio and video to stereo systems, TVs, and home entertainment centers throughout the house. Special-purpose computers called music servers can copy music from CDs or older recordings (such as cassettes or vinyl records) or download music files, store the music as digital files, and play them in any room in the house on demand, either through the speakers attached to a computer, through a traditional stereo system, or through a dedicated tabletop device similar to a radio. The same players can also receive and play streaming radio stations from around the world through the Internet. Video servers can store movies and other videos and make them available through the network to computers, televisions, and home theater systems. Some network music servers also include docking stations for iPods and other portable music players that can transfer files between the server and the portable unit and play music and videos directly from the portable device.
Audio and video programs can move through the network at the same time as email, web surfing, and instant messages.
For detailed information about setting up and using a home entertainment network, see Chapter 15.
A stand-alone video camera (often with a built-in microphone) connected to your home network can have several uses. You can place a camera at the front door to identify visitors, or use one in a nursery or playroom to keep an eye on your children from computers in other parts of the house. Other devices can use special sensors to detect smoke and fires, unlocked or open doors and windows, broken glass, or flooding and other problems and send alerts to the homeowner on a local computer or to a home protection service through the Internet.
Combined with a wireless network link, the same kind of security monitoring can extend to a detached garage, shed, or other separate buildings, even if the house's wired network does not reach those locations. Chapter 15 explains how to connect and use cameras and other security devices to your network.
Home automation systems usually use separate wiring from a household data network, but sometimes they're closely integrated. Home automation can be as simple as turning on outside lights after the sun goes down, or as complex as opening and closing drapes, monitoring and adjusting heating and air conditioning, operating a lawn sprinkler, or filling the dog's water dish. You can also expect the next generation of "smart" kitchen and laundry appliances to include network connections that will allow them to let you know when the roast is cooked or the clothes dryer has completed its fluff cycle.
Chapter 15 provides basic information about home automation systems and devices and explains how to connect them to a computer network.