Wi-Fi is the chief way to prowl the virtual corridors of cyberspace (or send e-mail, access the App Store or iTunes Store, or check out YouTube) on the iPad. But for all the places you can find an Internet hotspot nowadays — airports, colleges, coffeehouses, offices, schools, and yes, homes — Wi-Fi still isn’t available quite everywhere.

If you bought an older iPad model with 3G cellular, you often had a viable alternative when Wi-Fi wasn’t available. In the United States, such models from AT&T work with Wi-Fi, AT&T EDGE, and AT&T 3G. Verizon’s iPad 3G version works with Verizon Wireless’s so-called CDMA EV-DO Rev network. You can safely avoid the jargon. (iPads also work with another wireless technology, Bluetooth, but that serves a different purpose.)

Data plans vary and are subject to change. As of this writing, the AT&T pay-per-use plan ranges from $5 for a 250MB day pass to $50 for a 30-day, 5GB pass. The Sprint plans also start at $5. Verizon Wireless has a 1GB monthly plan for $20, with additional plans from there. Meanwhile, T-Mobile iPad users get 200MB of free 4G LTE data every month for as long as they own their tablet (even if they aren’t T-Mobile customers).

Cellular customers prepay for cellular access using a credit card. Fortunately, no one- or two-year contract commitment is required, as is most likely the case with the phone in your pocket. That means if you’re hiking in the Swiss Alps for a month, or otherwise indisposed, you don’t have to pay AT&T or Verizon or other carriers for Internet access you’re not using.

With the third-generation or later models that offer the cellular option, you’ll pay more upfront and whenever you need cellular service. But when a 4G network such as LTE (Long Term Evolution) is available you’ll be able to surf at a blistering pace.

Cellular-ready iPads also work on GSM/UMTS network technologies that perform outside the U.S., though you may have to pop in a SIM card to get it going abroad without Wi-Fi. Depending on your carrier and where you happen to be, you may see different network flavors, including HSPA, HSPA+, and DC-HSDPA — the fastest 3G and 4G networks out there as of this writing.

The iPad automatically hops onto the fastest available network, which is almost always Wi-Fi, the friendly moniker applied to the far-geekier 802.11 designation. And eight-oh-two-dot-eleven (as it’s pronounced) is followed by a letter — typically (but not always) b, g, or n. You see it written as 802.11b, 802.11g, and so on. The letters relate to differing technical standards that have to do with the speed and range you can expect from the Wi-Fi configuration. But you shouldn't lose any sleep over this issue if you haven’t boned up on this geeky alphabet.

The iPad Air and the iPad mini with Retina display also take advantage of two antennas and so-called MIMO (multiple-input multiple-output) technology to help connect you even faster.

For the record, because the iPad adheres to 802.11a, b, g, and n standards, you’re good to go pretty much anywhere you can find Wi-Fi. If you have to present a password to take advantage of a for-fee hotspot, you can enter it by using the iPad’s virtual keyboard.

To monitor your cellular network usage, tap Settings→Cellular Data→and peek at Cellular Data Usage for the current period. You can also view how much cellular data you used while roaming. And see how much cellular data you used for specific apps.

If you’re consuming a lot of data for a given app and can live without that app for a while, at least when Wi-Fi is out of reach, tap the switch to turn it off (gray will be showing instead of green). Tap the Reset Statistics button at the bottom of the Usage pane (you may have to scroll down to see it) on the day you start your monthly data plan.