A cap badge is a badge worn on the front of uniform headgear and distinguishes the wearer's organisation.
British cap badges I
British cap badges II
In the British Army (as well as Commonwealth armies), cap badges are extremely important, with every regiment and corps having its own. In some regiments, officers and other ranks have different cap badges. When a soldier is assigned to a regiment or corps, it is known as being capbadged to that organisation.