If it's clothing, shoes, purses, or back packs that's usually chrome tanned leather. It's usually flexible.
If it's knife sheaths, holters, saddles, or belts it's usually veg tanned.
You will find lots of terms like bridle, latigo, strap, oiled, most of the time this is referring to veg tanned leather.
Terms like pull up, garment, bag or chap leather will be referring to chrome tanned.
This list is not complete, or even completely truthful(given that a lot of terms are interchanged from one store to the next.
It's kind of a crap shoot you just have to struggle through in the beginning.
Springfield will be a Great place to start. You can even email them and get help.
Hope this helps a little. Keep having fun.