XO Sauce?

What’s XO sauce? Locals I ask all know it exists but no one can tell me what it is, what it’s made from, or what it’s used for other than to “put on food”.

I have a jar, and the ingredients are: banded coral shrimp, Jinhua ham, Japanese scallops, red onions, garlic, chili peppers, sunflower oil

This brand is put out by Lee Kum Kee, a hong kong company.

Lots of people have their own recipe. It’s basically just a spicy sauce/topping usually with a quite few seafood ingredients.