They're a bit similar... you can keep your options open for a few moves anyway (with e6 and b6) but it's where you put your king's bishop that really defines it. Bb4 is a Nimzo and Be7 is a queen's indian. They aren't variations of each other, they're separate openings.
Well... that's assuming white plays Nc3. If you play Bb4 without Nc3 then it's a bogo indian defense. Again these are all seperate.
If you did a set up not covered in any of these, but still played b6 and e6, I think it would just be filed under the english defense.
what are the Nimzo-Indian Defense variation names?


(edit, looks like I was a bit late)
The Nimzo Indian variations (the 3 main ones anyway) are classical (Qc2) Rubenstein (e3) and Kasparov (Nf3 before Nc3).
There's also a Spielmann, Leningrad, and probably a few others. You can always wikipedia openings, and for the major ones (like Nimzo), you can get a pretty good overview. Checking it myself they list a half-dozen variations I've never heard of heh.
What are the names of them? was one of them called the queens indian?