Hipparcus, in ancient Greece, was the first Astronomer to notice and quantify the visible differences in brightness of stars. He categorised all the visible stars into 6 groups of magnitudes. The brightest stars he placed in Magnitude 1 group and the faintest visible (to naked eyes) he placed in Magnitude 6 group. Modern day Astronomy techniques of measuring the brightness of stars continues with this basic scheme but, ofcourse, with sophisticated observing and measuring techniques, this classification into magnitudes extends to much finer gradations. We have stars, in the modern magnitude scales of measurements which are brighter than magnitude 1 (they may even go into negative magnitudes), fractional values of magnitudes assigned to stars allows for finer measurements and categorizations and finally, with the telescope opening our knowledge of fainter and fainter stars, the magnitudes of stars observed has increased from 6 to values above 20 for very faint objects seen with the largest of the telescopes in the world.