border control

A border control barrier is a wall, fence, moat, or other object along a land or water boundary which serves to prevent or reduce unwanted traffic across the border, including illegal or unchecked immigration, emigration, visitation, exits, or transfer of goods.

Border control refers to protection of a physical boundary, and differs from checkpoints at border crossings, which are either immigration control, emigration control, or customs control.

The object physically obstructs unwanted boundary crossings. A staffed checkpoint that inspects travelers or goods has a separate control function, even when it operates beside the barrier.