Quick Charge is a fast charging technology developed by Qualcomm, predating the widespread adoption of USB Power Delivery. It works by having a compatible charger and device negotiate a higher voltage over USB to increase charging speed beyond a basic charger's limits.
Many Android phones with Qualcomm processors have historically supported Quick Charge, and many chargers marketed for fast phone charging support both Quick Charge and USB PD to maximise compatibility across different phone brands. The two standards are not identical, though a phone supporting only one will typically still charge, just at standard speed, from a charger that only offers the other.
Over time, USB PD and its Programmable Power Supply feature have become the more universal approach across brands, with some newer devices relying on PD alone rather than Quick Charge. Checking a phone's specifications for which standards it supports helps when choosing a compatible charger.
