A badge is a device, patch, or accoutrement which is presented or displayed to indicate some feat of service, a special accomplishment, a symbol of authority granted by taking an oath (e.g., police and fire), a sign of legitimate employment or student status, or as a simple means of identification. They are also used in advertising and publicity.
Badges have become highly collectible: in the UK, for example, the Badge Collectors' Circle has been in existence since 1980.
The BBC children's programme Blue Peter also awards its own "Blue Peter badge" to members of the public who appear on the show. These are highly collectible as they cannot be bought - except from people who have been awarded one and wish to sell it.
Case badges are also thick (about 3 mm deep), 3 cm x 3 cm lucite stickers that are often packaged with various computer parts, such as processors and video cards. Modern computer cases are frequently embellished with an indentation on the case's front panel to facilitate the affixing of a case badge.
In work places employees are often issued name badges which identify them. Name badges are also commonly issued in high schools and hospitals. They are often used to tell legitimate workers from impersonators.
Badges can be made from a wide range of materials such as metal, plastic, rubber, leather and textiles. Textile badges, for example, can be either woven or embroidered.