Edging is when you pause the stimulation before you orgasm. The most basic is when you are jerking yourself off and you stop when you feel yourself getting to the brink. Doing that to someone else when you can't actually feel their arousal and how close they are is a real skill.
I've never really heard the term P O T before this thread, but in reading that article, I've certainly experienced it a few times giving and receiving. It usually involved a lady doing CIMSW. I would bust in her mouth and she didn't stop sucking. You are really sensitive at that moment and you kind of want her to stop, but you also don't. It's very intense, for me the most intense orgasm possible. Not sure what she goes by now, but back when I saw Lily Devine, she was great at this. I booked an hour, she kept there for a few hours, did that to me 3 times, and I think if I didn't have a wife at home, she would have let me spend the night and see how many times she could do that before I passed out or shot dust lol. More recently, I saw Melanie Richards in Woodstock and she did this to me, I almost needed to put a pillow over my head to muffle myself. She didn't swallow though, which was pretty good that she managed to hold all that in her mouth and do this and still breathe lol.
You might experience this from the other side when you go down on a woman and when she cums her immediate reaction is typically to push your head away. I've had a few gems where she grabs my head, but rather than push me off her, she pulls me tighter and grinds herself against my face while she cums. Usually loudly. My usual daty technique is to let her guide me when she cums. I typically will hold my tongue on her clit during climax and let her move against me to her tolerance, I don't even slightly move my tongue, just let her do what she wants. Unfortunately, my current fave lady has had too many guys just go to town when they eat her and now she really doesn't like being touched after orgasm. I've tried to even demonstrate when we start, I'll say "When you cum, I'm going to do this, do you trust me that that is all I'm going to do" and she'll be like "yes I believe you", then when the time comes, her automatic reaction is to pull away or put her hand between me and her pussy. It's a psychological barrier I can't get through, so there is no way she will ever be a P O T participant lol.