Dolly what do you call it? depending what the sauce is made from will give the name that I would call it and could be a sauce if tomatoes or cheese, gravy if a meat based. You are making me think and I will add to this later

Is Roux the word you are looking for? It's taking the oil or butter and adding equal amounts of flour to thicken the sauce or juice. There may well be another. I'm not a "fancy" cook. I've heard emulsification, but I don't know how to apply it.

Another one is a reduction. Hugs. Nan

I think this is a great question and I'm learning from it.

Thank you for your comments ladies but they arent what I'm looking for.... when you let a the pot cook, somethins on a higher heat so that you get a creamy type liquid..... it's hard to describe

Yummy!
Hugs Roberta

Hi Dolly, it's either a reduction as others have said or a Puree!! Love Chris
Here is a definition from the internet -

" A purée is cooked food, usually vegetables, fruits or legumes, that has been ground, pressed, blended or sieved to the consistency of a creamy paste or liquid."

Could it be "thicken"? You've really got everyone thinking on this!

deglazed??