sofa
A long, soft seat where several people can sit together.
A sofa is a long, cushioned piece of furniture designed for multiple people to sit on comfortably. You've probably got one in your living room right now, the kind of furniture where you might curl up with a book, watch a movie with your family, or just relax after a long day at school.
Sofas typically have a back and armrests, and they're upholstered with fabric or leather to make them soft and inviting. They're different from chairs because they're built for two, three, or even more people to sit side by side. A loveseat is a smaller sofa designed for two people, while a sectional is a sofa made of multiple pieces that can be arranged in different ways.
The word couch means essentially the same thing as sofa, though some people use “couch” for more casual furniture and “sofa” for fancier pieces. Either way, you're talking about that comfortable centerpiece of many living rooms where families gather, friends hang out, and fort-building happens on rainy Saturday afternoons.