Assembly Line: A manufacturing process in which parts (usually interchangeable parts) are added to a product in a sequential manner to create an end product. It's like the conveyor belt sushi bar where each chef adds their part before sending it down the line.
Mass Production: The manufacture of large quantities of standardized products often using assembly lines or automated technology. It's like printing multiple copies from one original document.
Working Class: People employed for wages, especially manual laborers and skilled craft workers. These were typically the 'chefs' working within these 'kitchen-like' factories.