From your description it sounds like a microphone polar pattern switch, which governs whether the microphone should only pick up sounds coming directly from the front, or whether it should record sounds from all directions. Usually there will be a "cardioid" position, which suppresses sound from the back.
The MAudio Sputnik and Solaris microphones both feature "selectable cardioid, figure-8, and omni polar patterns"
answer updated now we know which microphone we are talking about...
To understand the little pictures. The top of the diagram is the front of your microphone. It is a 360 degree plot of the responsiveness of the microphone from all angles - the further the point is from the centre, the louder the response is.
The omni pattern is the easiest to understand - it will pick up sounds equally from all directions. This is good if you are using a single microphone to try to pick up everything in a room.
The cardioid pattern attempts to accept sounds from the front, and reject them from the back. This would be useful for example when recording a single vocalist. It is important to know which side of your microphone is the "front" (usually has the manufacturer logo on it)
The figure of eight pattern rejects sounds from the side, but front and back can be used. So for example if you were recording two singers, one either side of the mic you could use that setting.