The Chemise original design was to keep sweat and body oils from staining and/or spreading to the outer garments. Most commonly the term refers to a loose-fitting, sleeveless undergarment or type of lingerie which is typically called a slip. It's usually unfitted at the waist.
The standard cotton and satin chemises are the most popular ones. A chemise typically does not have any buttons or other fasteners and is put on by either dropping it over the head or stepping into it and lifting it up. As lingerie, a chemise is similar to a babydoll, which is also a short, loose-fitting, sleeveless garment. Typically, though babydolls are looser fitting at the hips.