

For the info on why there are different descriptions of carbs: https://www.fda.gov/food/nutrition-facts-label/how-understand-and-use-nutrition-facts-label
What are Added Sugars and How are they Different from Total Sugars?
Total Sugars on the Nutrition Facts label includes sugars naturally present in many nutritious foods and beverages, such as sugar in milk and fruit as well as any added sugars that may be present in the product. No Daily Reference Value has been established for total sugars because no recommendation has been made for the total amount to eat in a day.
Added Sugars on the Nutrition Facts label include sugars that are added during the processing of foods (such as sucrose or dextrose), foods packaged as sweeteners (such as table sugar), sugars from syrups and honey, and sugars from concentrated fruit or vegetable juices. Diets high in calories from added sugars can make it difficult to meet daily recommended levels of important nutrients while staying within calorie limits.
Note: Having the word “includes” before Added Sugars on the label indicates that Added Sugars are included in the number of grams of Total Sugars in the product.
For example, a container of yogurt with added sweeteners, might list: Total Sugars on Sample Label
This means that the product has 7 grams of Added Sugars and 8 grams of naturally occurring sugars – for a total of 15 grams of sugar.
As to what various carbohydrates do? That’s a biochemistry semester, mate, but a quick look can be had here: https://rimgo.vern.cc/0EQF3.jpg
with a simplified version here: https://i.pinimg.com/originals/55/8f/f3/558ff3406b063c99f1868ef903217be9.jpg
Here’s a medium complexity: https://redlib.nadeko.net/img/yepntxvf89t71.jpg
If I’m going to give you a short, two sentence summary? Most organic molecules in the body can be broken down to a two carbon molecule attached to a coenzyme that we call acetyl CoA, and that can be used to build most products in the body when combined with other substances like nitrogen and sulfur. Carbohydrates typically go down one of three paths, either 1.) broken down to pyruvate before entering the Kreb cycle, where we produce most of our energy, 2.) broken down to pyruvate and then switched over to acetyl CoA and used to build lipids (fats), typically as a triglyceride, or 3.) shunted through the pentose pathway and used for various purposes, including killing pathogens and building/modifying nucleic acids.
In an interesting tangent, that’s actually a thing in brazil. If I remember, there are laws in place that make it illegal to operate a motorcycle without a wire cutter on it.