A pass-through has a door on each face. It is usually built into a wall or placed between two work areas, such as between a cold kitchen and a service corridor. Food goes in on one side and comes out on the other, so the two teams never need to cross into each other's space.
This layout supports one-way flow, a core idea in hygienic food handling: raw and prepared items move in one direction through the operation instead of doubling back. In hospitals and institutional kitchens, it also keeps service staff out of the production area. Because two sets of doors can be opened, temperature recovery and gasket condition matter even more than on a single-sided cabinet.
A hospital diet kitchen in Hyderabad might plate patient meals on the kitchen side, load trays into a pass-through, and have ward staff collect them from the corridor side. A banquet kitchen can use the same idea to stage cold desserts for servers.