A corset, a bustier, and a bra are all undergarments that can be used to shape and support the body. However, each of them has its own unique design and function. Corsets are designed to be worn as an outer garment and provide more structure than other garments. Bustiers are designed to provide more support for the chest area while also adding shape to the waistline. Bras are designed for everyday wear and come in various styles such as push-up bras or sports bras. Each of these garments has its own purpose and can be used in different ways depending on the needs of the wearer.