What is the difference between a hot rod and a rat rod?

A rat rod is built from unique, often home designed parts, built to reflect the owners personality. I do not mean to imply anything negative, because anyone who builds, and is into cars, to me, is unique, telented, artistic, and a friend indeed, however, rat rods, to me are more like the "ugly Betty" type of approach some women take. They use "not popular" parts, little chrome, and usually non gloss type of paints. They are usually powered by older engine/trans. combo's, and are not usually inspired toward racing. The phrase hot rod, is a wide open term. It basically refers to a car that is home built, and geared toward high performance, or drag racing. The opposite would be a muscle car.