Levis

Ok so I just started wearing Levi’s and I don’t get their sizes AT ALL! Idk if someone can explain it to me? Now to be clear I do know that there’s 2 numbers, one is waist size and the other is length. For example I’m pretty sure I’m a 28,30 but when I was shopping online today I saw that some jeans said like “710 super skinny” or “310 skinny” and I was wondering if the 3 digit number meant something specific for sizing? Like would be 28,30 size be different depending on the 3 digit number or is the number just part of the name of the Jean/ item number?

I don’t want to sound stupid but I really need to kno 😂 plus I thought I read somewhere on the site that Dixon is different for each pair of jean that has a diff 3 digit number.

Sorry if this was confusing and thx for helping in advanced