Good question!
Edging is something that is key to denial, but can be done without it. i.e. you can edge, that is take yourself right to the edge of orgasm, and do that a few times, and then in fact, cum.
Actually this is a great way to just play by yourself, with another, or just start to explore denial. Just explore how edging makes you feel, do it a few times with some breaks in between, and then finally reward yourself with a nice orgasm, which will usually be REALLY good as the edging intensifies it.
Denial uses edging to get and keep you horny, but the main point of it is you don’t cum at the end. Once you’ve got yourself horny and needy, then you can use other tricks like ‘no touch’ or playing without edging to keep you horny. Really it’s just a fun discovery of what works best for you.
But for most women, denial is fundamentally about edging, at least a few times a day, to keep that ‘high’ of arousal going as much of the day as possible.
Protip for guys: Learn to edge a girl well with your hand, mouth and cock and she will adore it. But yes, unless you know she’s INTO denial, you make her cum, a lot, at the end. Then, after a few times you slip in, ‘So… what do you think it would be like if I didn’t let you cum at the end, just left you horny and dripping until tomorrow?’