A mermaid-style wedding gown typically features a fitted bodice that hugs the waist, hips, and thighs, then flares out dramatically at or below the knee, resembling a mermaid's tail. On the other hand, a trumpet skirt wedding gown is also fitted through the bodice and hips but gradually widens into a flared skirt starting around mid-thigh.

The main difference between the two styles lies in the point at which the skirt begins to flare. The mermaid style tends to have a more pronounced and dramatic flare, emphasizing the curves, while the trumpet style offers a more subtle flare and allows for greater ease of movement.

Choosing between the two styles ultimately depends on your personal preferences, body shape, and the overall look you want to achieve on your special day. Both styles can be glamorous and elegant, so it's a matter of finding the one that makes you feel confident and beautiful.