railing

A structure made of a rail, often connecting a series of upright members, that is used as a guard or barrier or for support, as on a balcony or next to a staircase.

The rail of such a structure.

Rails considered as a group.

Rails collectively; a combination of rails; a construction in which rails form an important part.

Hence Any openwork construction used as a barrier, parapet, or the like, primarily of wood, but also of iron bars, wire, etc.