Apple's iPad and iPad 2 come in two basic models each: 3G and Wi-Fi. The Wi-Fi version uses standard 802.11 wireless networking to connect to Wi-Fi access points. The 3G version also has a 3G radio for wireless data transfer, just like the iPhone and other smartphones. Your specific needs and budget will determine which one you should buy.
What is 3G?
3G is the name for third-generation wireless broadband networks. It's primarily used by cell phones and smartphones to access the Internet. 3G networks run in conjunction with standard cell phone networks, allowing mobile access to the Internet in metropolitan areas and along most major highways and interstates. In the United States, AT&T and Verizon are the provers of the 3G data connection to Apple's iPad as of April 2011. The 3G is faster than the previous EDGE standard, but not as fast as more recent 4G systems, including WiMax and LTE.
Wi-Fi Vs. 3G
W-iFi is a short-range wireless protocol designed for laptops and other electronic equipment. While it's generally much faster than 3G as the typical land-based broadband Unternet connection far exceeds 3G's speed capability, the range of Wi-Fi is extremely short by comparison. The maximum range of a Wi-Fi access point is about 100 feet, and usually significantly less when the signal has to pass through walls or there are multiple users.
3G And Wi-Fi iPads
The standard iPad features only a Wi-Fi radio, and starts at £324 for the 16 gigabyte version. The iPad 3G uses a Wi-Fi and 3G radio, and starts at £408 with 16 GB. Aside from the addition of the cellular radio, the two models are identical. All hardware and software sold for the iPad, including apps, cases, keyboards and chargers ,will work with both units. Access to 3G networks starts at a price of £9 and goes up the more data you use. You do not need to sign a contract to access either the AT&T or Verizon 3G network. The iPad 3G will also work on Wi-Fi networks.
Which One to Buy?
Your needs and budget will determine your choice when you decide to purchase an iPad. If you intend to use your iPad on the road or in locations that don't have a Wi-Fi access point, you should buy the 3G model. If you intend to use it mainly at home or in the office, the Wi-Fi model is much more practical. The £84 price difference is considerable; even if you intend to use the iPad on the road, remember that you will still have access to stored music, movies and non-network apps. If you can go without the surcharge and the data access fee, you should consider doing so.