In this new epoch, one of the major problems addressed by the system biologist is the process of understanding gene regulation in different segments of biological environments. In a given cell, many genes expressed themselves and they work together to achieve the cell’s fitness, function, and survival. In order to ensure that they achieve the desired outcomes, the genes must express themselves in proper amounts and time. This being an important factor should be taken into major consideration. Gene Regulatory Networks (GRNs) aims at realizing the kinetics of the networks and mechanisms of the diseases that come due to dysregulation in cellular processes. The aim of this paper is to discuss various types of biological networks and to throw some light on the mechanism of gene regulatory networks and methodologies applied for the structure of gene regulatory networks. Though it is quite difficult to state which technique is more suitable as it varies from one domain to other but Bayesian networks are usually more suitable as they work with the concept of probability.