Many scientists have studies the formation of galaxy for many years. And all their studies and examination led them to one similar result; that galaxies were formed throughout the epoch when the history of the universe started. However, they could not find absolute evidence and therefore they have ended up forming two theories. These two theories are the theory of accretion and the theory of collapse. The first theory explains that the stars formed together to become a galaxy while the next one explains that the galaxy was formed out of the explosion of gaseous clouds. The first site of the galaxy formation was in late 1996 when the scientists discovered small stars forming into a cluster eventually turning into a galaxy. They believed that it happen 11billion years ago as well. That is why they cannot dismiss that gas collapse theory immediately because of the possibility that it could be right. However, they also consider the fact that there could be different ways to form a galaxy and not only according to the two theories formed.

When Hubble formed his classification scheme, he initially believed that every galaxy is a representation of different evolutionary stages which started from one form of galaxy and eventually formed into another. Although his theory proved to be true, the term he used in discussing about the gradual evolution is still something that needs to be evaluated. To say that the evolution of galaxy really existed is something that has been proven by the existence of the galaxies from different places and different distances. There are galaxies that takes places only at very distant places and these are the known as the quasars and the BL Lax objects. These existed a long time ago, particularly when the universe can still be considered younger although they do not exist anymore. This gave the astronomers the thought that the initial stages of the galaxies are the active galaxies.

It is undeniable that until now many scientists are still very keen on examining the formation and evolution of galaxies. Science sure wants to prove that their challenge to the evolution of the Earth is purely based on science and not because of something else. Their theories have been winding up, and although there have been theories that have proven to be wrong; there are also ones that have been proven to be related to the existence of the galaxies. The radiant manifestation of galaxies is closely connected to the theory of star formation as well as evolution. Obtainable theoretical study on star formation has, generally, been enthused by observations of the multifaceted environments of the interstellar medium in our galaxy. Current spectroscopic interpretations with the Keck telescope have established that high–redshift galaxies can be proficiently recognized by color as UV–deficient, because of strong galactic and intergalactic inclusion by hydrogen further than the Lyman–limit. Corresponding information regarding the history of the galactic gas as well as its metallicity is taken from the latest study.