Beachhea is a military term used to describe the line created when a unit (by sea) reaches a beach, and begins to defend that area of beach, while other reinforcements (it is hoped) help out, until a unit large enough to begin advancing has arrived. Sometimes used interchangeably (both correctly and incorrectly) with Bridgehead and Lodgement. Beachheads were very important in operations such as Operation Neptune, the Korean War (especially at Inchon), and the Vietnam War, among many other examples.