I need to draw stars. I currently have a game in ortho 2d much like galaga, but now I want to know how to draw stars that are maybe 3 pixel diameter at most like the background in galaga.

Are these point sprites? or is there another type to keep the processing low?

The easiest thing to do is use GL_POINTS, just to get something going. Next you can use a regular sprite (textured quad), rendered individually. Last, you can render the sprites batched (either via instancing, or ibo sprite batching.