Merchants deal with trade. That means they deal goods that they do not produce themselves, in order to get profit.
Merchants can be two types:
In the US, "merchant" is any person while engaged in a business or profession or a seller who deals regularly in the type of goods sold. Under the common law in the United States, merchants are held to a higher standard in the selling of products than those who are not engaged in the sale of goods as a profession. For example, when a merchant sells something, he or she is expected to give a warranty, guaranteeing that the product is fit to be sold, even if there is nothing in writing to this effect.