The term originally trademarked for a brand of adhesive bandage is Band-Aid.
Johnson & Johnson introduced the product in 1920 after employee Earle Dickson devised a ready-to-use dressing for his wife, Josephine, who often cut her fingers while cooking. The early design combined adhesive tape with a small absorbent gauze pad.
Band-Aid became so familiar that many English speakers began using it for any small adhesive bandage, regardless of manufacturer. That process is called genericization, or genericide. “Band-Aid” remains a protected brand name, so the generic description is adhesive bandage; the company commonly styles the name as “BAND-AID Brand.”
The brand is sometimes confused with Kleenex, Q-tip, or Jell-O, which are also famous trademarks often used conversationally as generic product names. In Britain, “plaster” is more common for the same type of dressing, while Elastoplast is another brand name that has acquired broad everyday use in some countries.