"Home Theater" probably has become a marketing term to sell consumer electronics, however, most people do not have an extra room just for a theater so the HT has to be within an already designated room such as living or family room. I do agree a HT should have a large screen, I mean that's one of the main attractions, or criteria, of any theater. Personally most of my HT set ups have had better surround effects than what I've experienced at the theater. I do think there's a difference between watching movies and a theater experience but I suppose it's all relative since no set in stone definition exists.