What is an avalanche fence?

Answer 1

Its when there is a barrier where avalanches are normally and it stops some of the snow getting down.

Answer 2

An avalanche fence is a barrier structure designed to prevent or mitigate snow avalanches by redirecting the flow of snow away from roads, railways, or buildings. It typically consists of steel posts and wire mesh or other materials that help to break up and slow down the movement of snow during an avalanche event.