The "Position:" (group) levels

[bgd77]

Hello,

I have seen that we all have a Position (also called Group in some posts) in our profile, that also appears when we post. Could someone explain in details all the levels that can be acquired (when someone gets a new level and why), starting from the lowest one to the highest one?

Thanks,
Bogdan

P.S. If it there is already such an explanation on the forum or in the help, I'm sorry.    I wasn't able to find it.