Dredging is the process of lightly coating a food, most commonly with flour, prior to cooking. While it’s similar to breading, the difference is that dredging is a light coating. You are not trying to cover the food with a thick layer as you would when using the breading process or a batter. Rather, you are using just enough for the ingredient to be covered with flour. (You can also dredge using cornstarch, alternative flours such as oatmeal flour or chickpea flour, or a breading like breadcrumbs, cornmeal, or even finely crushed crackers.)
So, the point of dredging is not to develop a crunching coating. That’s what breading is. Instead, dredging is a way to help foods brown, develop more flavor, and even helps prevent sticking. It is also a way to introduce a thickening agent (the flour), which can later be deglazed from the pot or pan, to create a slightly thickened gravy or sauce to compliment the dish.
This is why dredging your beef chunks in a little flour prior to searing the meat can level up your caldereta. With the little flour that you used to dredge the beef, you create an almost instant thickened sauce that’s already tasty without the addition of more ingredients. All that, just by doing an extra step at the beginning of cooking.
And while you can certainly use liver spread or allow the resulting tomato sauce-based sauce to reduce to create the thickened sauce of your caldereta, if you dredge your beef, you won’t need to–unless you want to.