This is a type of missile designed, strangely enough, to be fired from the surface and hit a target that's also on the surface. It is usually not applied to ballistic missiles; rather, to powered-flight, cruise, and most importantly guided missiles. Note that 'surface' can mean the surface of the land or the sea; ship-to-ship missiles are surface-to-surface, or SSMs. Some examples include the U.S. Harpoon missile, the French Exocet if fired from a ship, or the Soviet/Russian SS-N-22 SUNBURN.