Ring 0 is one of the privilege levels[?] in which an x86 processor can operate at any time. The others are rings 1[?], 2[?] and 3[?]. Of these most of the operating systems including Linux use only two levels, namely Ring 0 and Ring 3. Ring 0 is the highest privilege level and is the level at which the operating system kernel runs (kernel mode). Ring 3 is the lowest privilege level and is the level at which user applications are run.
... 11.9% have a female householder with no husband present, and 42.6% are non-families. 36.3% of all households are made up of individuals and 17.6% have someone living ...