Applesauce is made by taking the fruit of the apple, mashing it (or them) up, and cooking, until it is made runnyish, thus being able to tip over cooked food - like pork. If your apples are a little tart, your sauce may want some sugar, honey or other sweetening. Taste test before serving.
Applesauce wants to have some body however. If made *too* runny, it becomes Stewed Apple, which is more of a dessert, and usually has more sugar in it.