There are some differences between a hog and a pig, although many might not know because both words are referring to swine, and they belong to suidae family of mammals. However, the fact that they belong to the same family does not make them entirely the same. A hog is different from a pig. By definition, a hog is any animal belonging to the Suidae family of mammals, especially the pig, the warthog, and the boar. And it is used to refer to adult swine.
But a pig, which is even more common and available than a hog, is any of several mammalian species of the genus Sus, having cloven hooves, bristles and a nose adapted for digging; especially the domesticated farm pig. Pig is used to refer to a young swine. The major differences between a hog and a pig is in their age and size. Like I said before, a pig is a younger swine and a hog is an older swine. And as a result, you should expect a pig to be smaller in size than a hog. Most times, what farmers sell in the market is adult swine which is hog and not pig.