The term in colloquial usage refers to any kind of defended area that is extended into hostile territory – also called a foothold and sometimes the technically incorrect 'beachhead', which is frequently mistaken colloquially as synonymous terminology. The technical term refers in particular to the specific area on the far side of a defended river bank or a segment of a lake or riverine coastline held by the enemy forces, such as the Bridge at Remagen. The term is especially applied when such a territory is initially seized by an amphibious assault with the tactical intent of establishing a supply line across the geographic barrier feature to allow further operational manoeuvring. In that sense, it has much in common with the popular misconception of a beachhead.