How does a vacuum cleaner work?

An electric motor spins a fan that pushes air out of the vacuum’s exhaust, lowering the pressure inside. Air from the room, at normal atmospheric pressure, rushes through the nozzle to fill the gap, sweeping dirt with it. Bagged vacuums trap debris in a porous bag that lets air through, while bagless cyclonic models, popularised by James Dyson, spin air at high speed so dust is flung out into a bin. Filters, including HEPA filters, catch fine particles before the air is released. Rotating brush bars loosen dirt from carpets so the airflow can collect it.