Surface-to-air missile
A surface-to-air missile (SAM), or ground-to-air missile (GTAM), is a missile designed to be launched from the ground to destroy aircraft or other missiles. It is one type of antiaircraft system; in modern armed forces, missiles have replaced most other forms of dedicated antiaircraft weapons, with anti-aircraft guns pushed into specialized roles.
The first serious attempts at SAM development took place during World War II, although no operational systems were introduced. Further development in the 1940s and '50s led to the first operational systems being introduced by most major forces during the second half of the 1950s. Smaller systems, suitable for close-range work, evolved though the 1960s and '70s, to modern systems that are man-portable. Shipborne systems followed the evolution of land-based models, starting with long-range weapons and steadily evolving toward smaller designs to provide a layered defence that have pushed gun-based systems into the shortest-range roles.