Passthrough (architecture)
A passthrough (or serving hatch) is a window-like opening between the kitchen and the dining or family room. Considered to be a conservative approach to the open plan, in a modern family home a passthrough is typically built when a larger opening is either precluded by the locations of structural columns or is impractical due to the need to preserve the wall storage space.
Source: Wikipedia — Passthrough (architecture) (CC BY-SA 4.0)