The first thing you need to understand about applesauce is that it is a purée of apples. Your blender probably has a purée setting on it. If that is the case then you are on your way to making your own applesauce from scratch. If, however, your blender does not have a purée option you may have to resort to "blending" or "mixing" your apples. What you'll end up with could probably pass as applesauce, but will definitely have a different consistency than if it were puréed, in the same way that a hippopotamus is a different consistency than a rhinoceros
An important grammatical consideration is whether this stuff is called "applesauce" or "apple sauce"? Is it the sauce of an apple, or is it sauce made out of apples? Actually, since it comes from Germany you ought rather to call it apfelmus. Truthfully, though, you can call it any way you see it. The grammar police will let you pass go and get $200 on this one.
Culinarily speaking, you can leave the peel on or remove it before performing the purée process. It is still applesauce. Of course, leaving on the peel will add nutrition (the chest-hair growing kind, as my grandpa would've said. But then, he was Danish, not German). Also, it will give a reddish hue to your concoction, assuming you're using red apples. Otherwise it won't make a significant change to the color.
Traditionally, sugar was added as a sweetner, but honey was in common use, too. The value of
applesauce, in ancient days, was that it was a cheap and convenient way to save away the apple crop for later. This was important for surviving long winters, droughts or land wars with other European nations. Of course the ever-present worry of rhinoceros attack was certainly not on the mind of the average German, rhinos being indigenous to other parts of the world. Back to the original point, applesauce stores well and retains sweetness and nutrition for many months.
Applesauce was not exclusive to Germany, though. The Germans weren't the only folks clever enough to figure out the process. Many other Wester European and Scandinavian countries had their own varieties of applesauce, some thick, some thin, some chunky and some pasty. So, if you don't have a purée option on your blender you can still make the good stuff. It just won't be German. But that isn't germain, so long as it tastes good.
Now, how is it produced? Apples are heated - cooked actually - in water or, better yet, in apple cider. Once the desired consistency is reached sugar, spices and other ingredients may be added before mixing together. Lemon juice is sometimes added to give it a little zest. By the way, if you prefer apple butter it is essentially the same thing. The key difference is that apple butter has a higher ratio of cider to apples.
Apple sauce is not usually eaten as the main course. It is, of course popular as a side dish or on top of various meats, such as roasted pork, turkey or rhinoceros. We're all familiar with the "pork chops and apple sauce" moniker. It also makes a great topping for pancakes, waffles or french toast. Or eat it in a bowl with a little cinnamon or nutmeg sprinkeld on top!
Special bonus Item #1! Apple sauce is a valuable remedy for diarrhea. Apple seeds contain a substance called pectin, which is the active ingredient that brings this benefit. Since the seeds are not usually considered a delicacy, most of us don't eat a lot of them. But, in the process of making applesauce you get the seeds all mixed in!
Special bonus Item #2! In France they don't eat applesauce. Instead, they eat compote. Their apple compote is made by cooking apples in water or apple cider and then puréeing them. I think you get the point.
Special bonus Item #3! Applesauce makes a great homemade baby food! Babies love the sweet flavor!