what is PD 3.0 charging & PD fast charging ?

Dexinly USB PD 3.0. ... USB PD gives devices the ability to be charged or re-powered quickly. These devices must be charged over a USB connection. This power source allows compatible devices to share chargers as well.

Dexinly wall charger Power Delivery (PD) is a specification for handling higher power and allows a range of devices to charge quickly over a USB connection. ... For example, if you were to connect two phones that support Power Delivery with a USB-C charging cable, one phone could charge the other and vice versa.