Carbohydrates and nutritional label?

i always try to look at nutrition labels and see how many carbs there are. Now i know everyone says you should try to stay away from the refined sugars and stick to fiber. here is my question... i looked at a nutrition label and it says total carbs 25gm... under that it says fiber 8gm and sugars 2. 8+2 does not add up to 25. where does the other 15 grams go? what kinda carbs are the other 15? why dont they list them? how do i know if those are the good ones or bad ones. these labels confused me. what carbs are the ones i should be looking for... do i look at just sugars or do i look at total carbs when choosing... im confused...

The remaining carbs fall into the categories of starches (large chains of sugars), oligosacharides (medium chains of sugars), and sugar alcohols. They are omitted because they are not particularly good or bad for you.

Sugars are small, chains of one or two. They are also not particularly bad for you, but with sodas, candies, ketchup, etc it has become too easy to go overboard with them.

Fibers are listed because they cannot be digested, in other words you might as well take off 4 calories per gram. On top of that, they keep your digestive track healthy.

The net carb is the total carb grams, less the fiber grams.
So if something says 20 grams of carbs, 10 grams of fiber, you'd say the carb was 10.
Legally, not all types of sugars need to be listed as a sugar, so be careful when looking at sugar grams. If it doesn't add up, there are hidden sugars.