A well-established harmony in chaos

The origin and evolution of galaxies are closely linked to many different physical phenomena. Among them, the most important one is the environment they reside in. Isolated and cluster member galaxies indeed are affected by different forces which affect their evolution. The main concern of this thesis is to understand such forces and how they are related to galaxy evolution. Therefore, this thesis covers various topics including black hole mass calculations, the black hole mass-stellar velocity dispersion relation, the nature of AGN emission in galaxy clusters and field galaxies, a detailed investigation of X-ray and optical galaxy overdensity phenomenon, and the dynamical processes in pre-merging galaxy clusters.