Allowing urges: What this does to the brain

I think I have integrated the notion that the best thing we can do about urges is to allow them.

Doing this enough times will eventually defuse the urges altogether, so they will weaken in power and frequency — do I get that right also?

If so, do you mind explaining again for me the brain process by which this happens, i.e. how this works?

I think it will be helpful for me to stay motivated through the 100 urges, understanding what is currently happening in my brain.

Thank you!