Why is a switching type power supply less expensive and lighter than an equivalent linear power supply?

Switching power supplies work by converting the incoming AC mains power to DC, and then rapidly 'switching' it on and off at very high frequencies (typically tens to hundreds of kilohertz). This high-frequency AC is then stepped down by a transformer before being rectified and filtered back to DC. The key advantage of this process is that transformers, inductors, and capacitors become drastically more efficient at higher frequencies. As a result, the physical size and weight of these magnetic and filter components can be reduced significantly compared to a traditional linear supply operating at a low 60 Hz mains frequency. While switching supplies are lighter and more efficient, they actually require robust output filter circuits to suppress the high-frequency RF noise generated by the switching process. Therefore, the idea that they do not require output filters is a misconception.