Your Mac can communicate with a wireless base station up to 300 feet away, much like a cordless phone. Doing so lets you surf the Web from your laptop in a hotel room, for example, or share files with someone across the building from you.
Chapter 16 has much more information about setting up a WiFi network. The real fun begins, however, when it comes time to join one.
Sometimes you just want to join a friend’s WiFi network. Sometimes you’ve got time to kill in an airport, and it’s worth a $7 splurge for half an hour. And sometimes, at some street corners in big cities, WiFi signals bleeding out of apartment buildings might give you a choice of several free hotspots to join.
Your Mac joins WiFi hotspots ...