The word "pins" is a catch-all used to describe military badges and insignia for various armed forces around the world. Because these badges and insignia are routinely pinned to a soldier's or officer's uniform, they are frequently referred to as pins. But insignia can also be found on patches, so the terms are sometimes used interchangeably.

In the United States, Civil War insignia and pins are of great interest to collectors. While Union pieces are relatively common, Confederate insignia are quite rare and correspondingly expensive. In both cases, cloth insignia are hard to come by, while brass pieces present a different problem. Since brass Civil War insignia have been widely reproduced for 20th-century reenactors, in many cases from the original dies, it can be difficult to tell originals from well-worn, used reproductions. For this reason, serious collectors look for recently “dug” items, because 150 years of corrosion is difficult to mimic.

Insignia showing rank is the most common type, but again, because rank insignia were made of fabrics such as worsted and wool, these pieces are tough to come by. Chevrons sewn to... the arms of military jackets can be found in pairs (for corporals) and trios (for sergeants). For Union troops, yellow stripes designated calvary while blue meant infantry. Rank was also communicated via shoulder straps and insignia worn on an officer’s epaulettes.