Wi-fi is a way to connect to the internet wirelessly. In case anyone asks you, and they probably won't, the term Wi-Fi is a goofy name that was invented just to be catchy, and is sort of a take on the old term "Hi-Fi" (which meant high fidelity for music). The "Wi" is Wi-Fi is for Wireless, the "Fi" means nothing. A lot of computer terms are like that.
Anyway, in order to use it, drive over to your local Starbucks and sit down at a table. Actually, it works in the parking lot, too. The radius is about 30 feet on average. This is how you do it:
Take out your Wi-Fi enabled device. I used my Nook yesterday. If you're wondering if your device (tablet, laptop, ereader) is Wi-Fi enabled, it will tell you. All devices are different, but on my Nook, I went to "Settings" and "Wireless". In the future I'm sure that there will be a big button that says "Wi-Fi", but as of this writing, you have to look around a bit.
Starbucks, iHop, Burger King, and many other places have Wi-Fi and they do not require a password. You don't have to pay anything for this convenience, but it would be nice if you would go up to the counter and buy a cup of coffee. Sitting at a Starbucks surfing the internet or reading an ebook is very pleasant, and I highly recommend it.
And what the heck, go ahead and get that Grande Latte Decaf Espresso! Enjoy!