What is the difference between a couch and a sofa?

One of the most frequent questions we get while showing visitors around the showroom is what exactly is the difference between a couch and a sofa. Some people think that couch is a lower class term and sofa is used by upper class people, but we havent found that to be true. Well, the answer is right now they mean the same thing. Originally though, couch was used to mean furniture that one lay on coming from the word coucher in French which means lying down. Over time that has developed into the same meaning as sofa and can now be interchanged at will.