How does a PC Power Supply Unit convert AC to stable DC and why does 80 PLUS matter?

25 Tem 16:00

Can someone explain how a power supply unit (PSU) actually converts AC mains voltage into stable DC rails for a gaming PC? I'm particularly interested in the roles of the transformer, rectifier, filter stages, and why the 80 PLUS efficiency certification matters beyond just power draw numbers. How do these components interact to keep voltage ripple low and protect components?