Others control such things as the current viewing and projection transformations, line and polygon stipple patterns, polygon drawing modes, pixel-packing conventions, positions and characteristics of lights, and material properties of the objects being drawn. Many state variables refer to modes that are enabled or disabled with the command glEnable() or glDisable().
Each state variable or mode has a default value, and at any point you can query the system for each variable's current value. Typically, you use one of the four following commands to do this: glGetBooleanv(), glGetDoublev(), glGetFloatv(), or glGetIntegerv(). Which of these commands you select depends on what data type you want the answer to be given in. Some state variables have a more specific query command (such as glGetLight*(), glGetError(), or glGetPolygonStipple()).