A corset is a restrictive garment specifically designed to reduce the waistline and emphasize your curves.
Yes, corsets are designed to be form-fittingbut not thatdangerously form-fitting.
It is unregulated use of corsets that don’t fit that can lead to problems, perE-Times.

Bustiers usually have built-in bra cups to help outline and push up the bust.
Bustiers are not that restrictive, perParfait.
Also, while corsets can either be overbust or underbust, there is no such option for bustiers.

This design peculiarity means that when these two garments are placed side by side, they look very different.