He is using that heading to describe all the pictures he posts. For most part the majority of the pictures are modified or altered versions vehicles that never existed in the states he shows only a few are original restorations like this one.

Here is what Wikpedia says

Hot rods are typically American cars with large engines modified for linear speed. Nobody knows for sure the origin of the term "hot rod." One explanation is that the term is a contraction of "hot roadster," meaning a roadster that was modified for speed. ...