Am I using a fast charger? Why is my phone charging so fast?

Hi everyone!

This might sound like a dumb question, but I'm genuinely not sure. I upgraded from my iphone 8 to the iphone 13 pro a few months ago and I have noticed that my new phone charges insanely fast when I plug it into a plug socket. I use the usb-c to lightning charger cable that came with the phone and I purchased the 20W usb-c power adapter from apple separately. When I charge my phone now it charges so fast, it goes from 15% to like 60% in less than 20 minutes. Is this normal? When I use my old usb lightning cable and charge my phone through my laptop it charges very slowly. I know that it will charge slower through my laptop, but when I charge it normally with the 20W power adapter it charges so much faster than my old phone, it's insane. Is that the case because I am now using a larger 20W brick (as opposed to the old, smaller brick that came with the iphone 8) or am I accidentally using a fast charger? I'm asking because I know fast charging isn't the best thing for your phone and I don't wanna be fast charging it every day.