a rope, or series of ropes, anchored to the mountain at one or more points to aid soldiers over steep, exposed terrain; usually installed by lead climbing teams (normally Level 2 qualification)
A rope, often a real climbing rope, left in place by previous hikers to help others get up or down some difficult spot such as a wet, slick rock in a canyon or a slippery step-up in a cave.
A rope anchored to a route by the lead climber and left in place for all who follow. May also be left by an unknown climber for an unknown length of time. Used to ascend and descend the route when the climbers want to sleep on the ground or are shuttling gear up.
A rope anchored to a route by the lead climber and left in place for others who follow; a mechanical ascender or, on a traverse, clipped-in carabiners sliding along the rope can be used for extra climbing assistance and protection.
Fixed rope is the practice of fixing in place bolted ropes to assist climbers and walkers in exposed mountain locations. Used widely on American and European climbing routes but disdained by the purist mountaineer. Many guided expeditions to any of the eight-thousanders will normally setup fixed rope on steep and/or icy sections of the route.