Apple identifies all its iPads with "iPad" on the back. Not "iPad 2." Not "The New iPad." Just "iPad." As simple as this naming convention seems, it can cause plenty of frustration--just ask anyone who's ever tried to tell two seemingly identical iPads apart. Argh. It's easier than you think to find an iPad's model number--but you might need a magnifying glass.
Apple's model numbering system for the iPad denotes which generation iPad you have, as well as its wireless connectivity capabilities (whether it's a Wi-Fi model or has Wi-Fi and cellular modules inside). This is different from the SKU, which also denotes your iPad's storage capacity, color, and so on.
The model number is stamped onto the device itself. These model numbers usually start with the letter A and are followed by four digits. You can find this number on the back of your iPad: Flip it over, and look for the "iPad" label toward the bottom. You'll find the model number and serial number in this small text, and on older models, your iPad's storage capacity.
Here's a chart to help you understand what it all means:
The "MM" version of the cellular-equipped fourth-generation iPad and iPad mini refers to models with CDMA compatibility. If you use one of these iPads on Verizon's network, the MM version is probably the one you've got.
Identifying a model by SKU can be a little hit and miss--it all depends on what you can dig up in a Google search--but if you want to glean what model iPad you have that way, open the Settings app, tap General, then tap About. Look for the line labeled Model: Type the alphanumeric string next to it into your favorite search engine, and you should be able to glean some information about which iPad you have.