Regular Sofas: Regular sofas come in various sizes and usually fit 3-4 adults. They fit comfortably in most living rooms.
Sleeper Sofas: Sleeper sofas usually take up about the same amount of space, folded up, as a normal sofa would. But, sleeper sofas, or sofa beds, contain a bed which folds out of the frame in order to create a cozy guest bedroom where there wasn't one before. Usually the bed is large enough to comfortably support two adults.
Sectionals: Sectional sofas can usually hold a ton of people. Depending on the shape they may wrap around corners to enhance or define a gathering area, and they can separate to allow for a change in design.
Loveseats: Loveseats are smaller sofas that usually comfortably sit two; they may fit more easily into a smaller room.
Futons: Futons serve the same function as a sofa bed, but do so in a simpler manner. With a futon the mattress often doubles as the cushion and just needs to be unfolded to transform the couch into a bed.
