The terms gantry crane and overhead crane (or bridge crane) are often used interchangeably, as both types of crane straddle their workload.
The usual distinction drawn between the two is that with gantry cranes, the entire structure (including gantry) is usually wheeled (often on rails).
By contrast, the supporting structure of an overhead crane is fixed in location, often in the form of the walls or ceiling of a building, to which is attached a movable hoist running overhead along a rail or beam (which may itself move).
