There are several different kinds
Section honey is where small pieces of comb have been drawn and filled with honey into some form of container that has been placed in a hive by the beekeeper for that purpose. That is about as good as I can describe it.
Sections take a variety of forms, including the traditional wooden frames that are either square or oblong, depending on the country of origin. In the U.K. and Ireland they are 4¼ inches square. There are a number of proprietary plastic versions produced, but to the best of my knowledge all are for Langstroth hives. There are also round sections and there have been a number of designs of these produced too.
There are specially designed section racks, or supers, that take a number of sections, although there can be a small number placed in hanging section frames.