An epaulet is a decoration that is attached to the shoulders of a uniform. If you are a guard at Buckingham Palace, you have pretty nice epaulets on your uniform, but they aren’t as amazing as that hat.
The noun epaulet comes from the Late Latin meaning of spatula, “shoulder blade.” Any fancy extras attached on the exterior shoulders of a garment can be called an epaulet. Epaulets often have gold braided embroidery. Or stars. Some have fringe. The epaulets on the uniforms of airline pilots have four rows of braids, which distinguishes them as a higher rank than co-pilots, who wear three braids.