The iPad 3 had a Retina display, the iPad 2 did not. If you can see the pixels on the screen, you have an iPad 2; if not, it's the iPad 3.Same. I thought my iPad was either 2nd or 3rd generation, since it doesn't have the Lightning port compared to the 4th generation.
If you mean the black plastic area at the top of the back and top of the case, that's the cover for the cellular antenna and is also present on the cellular version of the iPad 2.
You can find out exactly which iPad you have by checking the back cover and comparing the model number with Apple's support page (check the 3rd list item in each iPad listing): Identify your iPad modelWell, I tested out to see if it had Siri, and it did. So I guess it's an iPad 3.
The link I posted lists all iPads.. going back to the first generation. Perhaps try that link again.I tried to do that when I wondered why my iPad wasn't upgrading to iOS 10. I then realized that it was only for iPad 4 models, which had the Lightning port instead of the original wide port.