If you don't collect c&s there is no reason why you should know what they are. After all, I haven't the foggiest idea why the words crest and seal are used.

I bet you can't find 3 people to agree on the same definition of a c&s.

I don't even know if anyone else agrees me on my definition.

Two of the "fathers" of collecting c&s (Allan Myers & Robert Eisenstadt) have displayed chips as c&s which I disagree with.

With all this confusion, you have absolutely no reason to feel dumb.