What is a "double-breasted jacket"?

A double-breasted jacket is a type of formal or semi-formal jacket that has two rows of buttons on the front, with the outer row overlapping the inner row. The front of the jacket typically has a peak or notch lapel, often with a wider stance than single-breasted jackets. Double-breasted jackets may have up to six buttons, although four or six is most common. The jacket may have flap pockets or welt pockets, and the back of the jacket may have a center vent, side vents, or no vent at all. They are typically made of suit fabrics like wool and are a classic and sophisticated wardrobe item that can be dressed up or down for various occasions.