What is Double Breasted
Something to do with a chicken? Possibly, but I don't know my poultry terms. So let's move onto clothing.
Double Breasted as opposed to single breasted? Single breasted is the "normal" everyday suit you think of when you picture one in your head. Left side and right sides come together in the middle of your torso and button together. Usually one column of buttons ranging from one to three. Note: on a single breasted jacket, DO NOT BUTTON THE BOTTOM BUTTON! Pretend that button doesn't exist. Yes, I know, I see sportscasters and news anchors do this quite often...but it is incorrect. Iv'e been told that sometimes they do that because it keeps the jacket closed up as much as possible so you don't see that they have shorts on- whatever the reason, don't follow their lead.
Double breasted has overlapping front panels and two columns of buttons, where usually only one column is functional. Most times you can button the jacket up either way left over right or right over left. Often there is also a button on the inside to strength the the hold of the jacket (that button is called a jigger). Typically when someone has a double breasted jacket, it is styled with a peak lapel rather than a notch lapel.
The difference is below. A peak lapel has a point or a "peak," and a notch does not.
You can also have double breasted vests. The double breasted vests overlap, and the single breasted vests do not. I would persuade most of you to stick with the normal single breasted vest. A double breasted vest can make your torso appear boxier, which is not ideal. Double breasted vests look best on smaller and/or thinner individuals, even then, I would still suggest that most people stick with the single.