By definitions, frame drums seem to have a beautiful simplicity - a hoop with drum head, a diameter larger than its depth. But...of course it's way more complicated than it is simple.
Leaving aside the nuanced specifications (bearing edges, shell materials, head materials, diameter, depth, etc.), and all the possible accessorizing (jingles, bells, snare strings),the names for similar drums played cross-culturally can be a quite confusing and slippery thing.
Daf, Daff, Duff, Deff, Tar, Bendir, Bodhran, Dayre, Daire, Doyrah, Riq, Riqq, Reqq, Rik.... Tar(Arabic) (Bahraini)/(Ma)Tari or (Ma)Twari (Swahili).
It's so easy to make a "mistake."
Early on, Cooperman started using the arabic name tar, but more than anything, we learned to be open-minded and flexibile. For many cultures, their native frame drum is carefully defined - emblematic, iconic. We have often been shown a drum that a drummer has brought back to us from another country/culture. There has always been a certain anxiety-of-influences when we would set about to make a Cooperman version. Drummers would compare their "real" drum - a "real tamburello" or a "real kanjira" etc. - to distinguished a drum made in a native culture other than our own. We never felt our drums were not "real" but we do respect the context.
A good example in the Cooperman line is the signature Glen Velez "bodhran." 
Glen brought to us the idea of a larger, bass range, frame drum - in his thinking, a "bodhran." In our world, Glen gets to call his drums whatever he wants to, but for many celtic drummers the Cooperman/Velez "bodran" is simply not a "bodhran."
One of the more generous reviewers suggested that our Velez model is a "neo-bodran." OK - we can be happy with that - it's an amazing drum!
Randy Crafton once tried to help me with this knotty language-thing - (certainly from a performer's perspective) maybe a good way to think of the various drum designs is to think about how they are being played instead of the thinking about the object specifications. 
Think about the drums as performatives. For example, our Asheville Rhythm Series drums and our new Krista Holland drums both have two thumbholes. So, we now have a tar drum able to be played like riq in a classical (aka "soft") position - so maybe we can say that the drum can be "riqed."
Another neologism: Cooperman has always used the term "jingled drum" to distinguish something like the riq and the ghaval from a tambourine. That is, an instrument where drumming (maybe drum head) action is "forward" of the shaken jingle sound. Think of our first "fusion tambourine" - our first Artist Innovation Series "drum" - the signature Jamey Haddad Hadjira?
Is it a drum or a tambourine ? We think of it more as of a drum than a tambourine, but it is unarguably an amazing thing manifested by Jamey and the Cooperman craftspeople.
anyway...
"You like potato and I like potahto,
You like tomato and I like tomahto;
Potato, potahto, tomato, tomahto!"
