Your social level is a numerical rank that indicates how infamous or famous you are. Social level is NOT correspondent to character level, but rather by both your character’s actions and the actions of the party. Social level is used as a measure of how certain segments of society will treat you. Heroic actions tend to raise social level, whilst the reverse tend to lower it.
Mechanically, your social level has no statistical effect on your character besides on certain social skill checks. Furthermore, certain situations may arise in game as a result of a character having a high enough (or conversely, low enough) social level that would not occur otherwise. In addition, a handful of feats and prestige classes may require a certain minimum social level.