Yep, there's a difference. Your 'Maid of Orleans' is a cultivar of the species Jasminum sambac. A correct label would read: Jasminum sambac "Maid of Orleans". The other plant should be labeled as Jasminum sambac. The common name of the latter is sometimes called Arabian Jasmine (or similar).

Of course, your plants could really be mislabeled and the latter plant could be yet another cultivar called 'Arabian Knights or Nights'. There are lots of J. sambac cultivars.

Got it? Or confused?

Rhizo, have you ever seen the Dave's Garden page for Maid of Orleans and the species form, Arabian jasmine? I have a feeling there might be confusion with the two, such as them being mislabled as either. Some people might have posted Maid of Orleans pictures in the species profile and vice versa thinking they have one or the other.

I myself cannot even say what is the difference between the two. And I ponder, is Maid of Orleans really just a name with no special characteristics differentiating it from the species? I am not sure about that. At least with Arabian Knights, and other sambac cultivars, they have unique features such as being double.