What is a short sale? How does a short sale in Real Estate Work?

https://youtu.be/lBrwX6ebl3E
https://www.sdshortsaleexperts.com/short-sale/learn-about-short-sales/what-is-a-short-sale ; my source: https://syndicator.myimplace.com/what-is-a-short-sale-how-does-a-short-sale-in-real-estate-work/