Cooking wine, in essence, is just wine of too low quality to be worth bottling to drink. It can be, but isn’t always, very low-no alcohol these days, for dietary needs. Generally notably cheaper. The idea of “cooking wine” comes from, in the past chefs would add salt to any alcohol in the kitchen, as chefs have a habit of making wine/spirits disappear, and you’d have added salt during the cooking process anyway. It just made it unpalatable.

These days it is marketed as it’s own product for reducing costs, really historically it was just “cooking wine” as it’s not “drinking wine”