I have found a website that explains these two techniques much better than I can. Click this link and it will take you to the complete article. Living Homegrown
The Two Best Sauce Techniques:
Deglaze a pan & make a quick sauce (small quantity)
Create a reduction sauce (larger quantity & more layers of flavor)
People sometimes get confused about the difference between deglazing the pan and making a reduction sauce (I know I did when I was first in cooking school).
Here’s the deal: Deglazing a pan is the first step in creating a reduction sauce – so they are actually related. But either one can be used on their own. When you are in a hurry, you can just deglaze a pan (instructions below) and add some jam to create a fast and simple sauce that can be poured over meats. If you have a bit more time or if you need more than a 1/3 cup of sauce, continue on
to make a fullblown reduction sauce that will blow your taste buds away. It is also easy, but takes a bit more time. However, you are rewarded with more depth of flavor.
Below I’ve outlined each so you can pick the method you want based on your time and how much sauce you need. And remember…just about any jam/jelly or marmalade will work.