Marines, or naval infantry, are soldiers who specialise at operating in littoral zones, both on land and at sea. Historically, the main tasks undertaken by marines have included raiding ashore in support of naval objectives, and the boarding of vessels during combat or capture of prize ships. Marines also help maintain discipline and order aboard the ship. In most countries, marines are an integral part of that state's navy.

Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or potentially hostile shore at a designated landing beach. Through history the operations were conducted using ship's boats as the primary method of delivering troops to shore. Since the Gallipoli Campaign, specialised watercraft were increasingly designed for landing troops, material and vehicles, including by landing craft and for insertion of commandos, by fast patrol boats, zodiacs and from mini-submersibles. The term amphibious first emerged in the United Kingdom and the United States during the 1930s with introduction of vehicles such as Vickers-Carden-Loyd Light Amphibious Tank or the Landing Vehicle Tracked.