Slipcovers are clothes for furniture.
You can change the look of your room according to season or mood. As clothes they can follow distinct fashion, they can be tight or loose. There are different views how slipcovers should fit. The traditional view is that it should fit tight; wrinkle-free to look like upholstery. The other view fit more with the English country style; loose and baggy. The American style is a compromise not too tight and not too loose.
There are many reasons to use slipcovers; the ability to refresh a look of furniture or a room quickly and inexpensively. Protecting good furniture, or covering worn out furniture and upholstery. Removable covers are easy to clean.