Vocabulario básico: partes de un tren en español

What does “ventanilla” mean in Spanish?

A house or building window is la ventana. But the window on a train, bus, car, or plane is la ventanilla. The ending -illa usually makes a word smaller, and that is where ventanilla comes from — a “little window.” Over time it became the normal word for any small window in a vehicle, so on a train you ask for a seat junto a la ventanilla (“by the window”).

The clip lists la ventanilla among train parts like el asiento (“the seat”) and el pasillo (“the aisle”). Ventanilla also names a service window where you are served through glass — a bank counter, a ticket booth, or a government desk. So one small word covers both vehicle windows and service windows.