To braise means to cook in a vegetable-seasoned liquid. The vegetables may be any combination of carrots, celery, onions, shallots, parsley, or mushrooms; or any single one of these.
The liquid used may be wine, stock, water, tomatoes, or the cooking liquids from other foods that complement the food being braised. The liquid used in braising becomes the sauce.
The food may or may not be larded, marinated, or pre-fried depending upon the quality and the type of food being braised. For example, you might sear a rump roast and then put it to braise, but you would not sear fish steaks.