What is PPS charging?
A USB-C mode where the phone asks for an exact voltage, in 20 mV steps, instead of picking from a fixed menu.
Fixed rungs waste the difference as heat. PPS asks for the exact voltage instead.
The menu problem
Ordinary USB Power Delivery offers a short menu of fixed voltages: 5, 9, 15, 20 volts. The phone picks the nearest one it can use and burns off the difference as heat inside its own charging circuit. PPS, short for Programmable Power Supply, lets the phone ask for the voltage it actually wants, adjusted continuously in 20 millivolt steps as the battery fills.
Why Samsung insists on it
The practical result is less heat and, on phones that require it, a much higher charging speed. Samsung's Super Fast Charging 2.0 at 45 W only engages over PPS; without it a Galaxy S25 Ultra falls back to 25 W or less no matter how big the charger is. Recent Pixel and iPhone models also negotiate better with PPS, though they are less strict about it.
What it is not
PPS is a property of the charger and the port, not of the cable. A cable cannot add PPS, but it can cap the current below what PPS wants to deliver.
a PPS range printed on the charger, such as 3.3-11 V / 5 A. The voltage span matters more than the headline wattage.
a multi-port charger where only one port supports PPS. Plug into the wrong one and fast charging silently disappears.