If you by chance have high-speed Internet in your home and you have more than one computer, or if your only computer is a laptop, then you need a wireless router. A wireless broadband router is just a small box that has one Ethernet network port, for the Internet modem, and three or more networking ports for other computers or devices. It is the controller box allowing a single Internet account to be shared with other computers. Having a wireless router means that you don't to run network cables throughout your house or where ever you want to surf the net.
The universal term for this type of wireless networking is called WiFi and what Apple calls Airport. It is sometimes also referred to by its IEEE name of 802.11. Even that doesn't narrow it down enough because there are several flavors of WiFi out there. The first version available was called 802.11b and Apple helped to bring WiFi to the home when it introduced the original Airport base station several years ago. It was priced well below other WiFi routers at the time.
Wireless 802.11b is able to transfer data up to 11 megabits per second, or Mbs. This is more than fast enough for most high-speed Internet connections, which are anywhere from 256kbs to 3Mbs. Of course we always want to go faster, so soon after there was a g version and today we have n. The g version, the most popular at the moment, is much faster with speeds up to 54Mbs. The newest version is n which has not had its specifications finalized yet. (Don't let that sway you, most 802.11n wireless equipment should be upgradeable with when an n standard is reached.) 802.11n is said to reach speeds up to 300Mbs.
All new Macs, and those sold in the last few years, have Airport wireless built in. The latest Macs have the new 802.11n, while slightly older Macs will have 802.11g (older still Macs will have 802.11b). All of these flavors are backwards compatible so you don't have to worry about whether your hotel or Internet cafe supports your Mac.
Apple has several wireless routers available. The Airport Express is the smallest and least expensive at $99. It works as either a wireless router, without the extra networking ports for sharing, or as a wireless extender for an existing wireless router. This means that if you have an Airport, or other WiFi router, but the signal does not reach the other side of the house, the Express just plugs into an outlet and acts as a repeater. There is also a USB port for a printer that can then be shared over the network. The Express is also unique in that it has an audio out jack that allows you to listen to your iTunes library stored on your Mac in another part of the house. Just connect a cable, available from most electronics stores, to a set of powered speakers or your home theater.
The Airport Extreme is a full-sized network sharing router priced at $179. It has one input port for the Internet plus three more Gigabit Ethernet jacks for sharing with other computers or printers. Since all Macs now have Gigabit Ethernet built-in, a Gigabit router allows for extremely fast computer to computer networking. There is a USB port to connect and share a printer or external hard drive.
Both the Extreme and Express now use the 802.11n standard. The n type of WiFi is much faster and it has a much greater range, 2-3x the range of 802.11g. Apple also makes a wireless router called the Time Capsule. This looks similar to the Extreme but has a hard drive built-in for use with Leopard's backup software called Time Machine. It is available with either a 500GB or 1TB (that's 1000GB) hard drive. These start at $299.\\Since WiFi is a universal standard, you do not have to buy an Airport to get wireless networking with your Mac. There are some great WiFi routers available from Linksys, Netgear, Belkin, SMC, D-Link, and US Robotics. Of these I really like the Netgear and Belkin. Netgear makes great routers and setup is very simple. Belkin makes some of the best 802.11n routers, the chipset they use is excellent and very compatible with most computers. The Netgear WGR614 is a great g type router and can be found for less than $50. The Belkin F5D8233-4 is an 802.11n router, what is call Draft-n, with dual antennas. The Belkin is priced under $80.
As you can see, Apple WiFi is priced quite a bit more than these other model. While the box may not say that the router is Mac compatible, you shouldn't have much, if any, problem setting one up. The Apple Airports are designed to work with all Macs. There is dedicated Airport software that is part of the Mac OS, making for easy setup. The other wireless routers are configured through a web browser, like Safari or Firefox, and usually have a wizard that walks you through the setup process.
When setting up your router you will want to pay close attention to security. The great thing about Linksys, Netgear, and Belkin is that they are very popular routers and you should be able to find plenty of help online if you have problems. There are a couple types of wireless security, the only one you want to use is WPA, its the most secure. By using WPA security, you will stop anyone outside your home from accessing your Internet and worse yet accessing the files on your computers. Of course this is more important is you live in an urban area or apartment building.
No matter which router you choose, the ability to take your laptop from room to room and surf the net at high speeds is really amazing. You can use your computer while watching TV in the living room, on the back patio watching the kids, or even in bed. Wireless is freedom from wires. Now if only we can figure out how to have wireless power.