The article presents a latest literature review on issues related to the automatic voltage regulators (AVR), conventional methods for voltage regulation, application, and advancement in Voltage regulation techniques. The article also includes review of optimization of the AVR with different controllers used by researchers for efficient performance of the power system. Modern-day power system networks are intricate plus prone to a number of risks. The networks are vulnerable to instability because operating a power system is complex and unreliable. One of these problems is rotor-angle instability, which, if correctly resolved, could cause system failure. AVR is vital for the operation of power systems. Automatic voltage regulators are utilised in power systems to keep an alternator's terminal voltage at a set point. AVR controls the evenness of the terminal voltage by adjusting the generator's exciter voltage. A power system stabilizer (PSS) is essentially a power oscillation damping (POD) regulator that is used to increase rotor angle stability. AVR PSSs must be properly designed, which is a difficult yet necessary process. Several approaches are put out in the literature for the effective blueprint of PSSs or POD controllers. This provision includes an up-to-date overview of the AVR and PSS as well as optimisation methods. Based on this review, it can be imparted that there is plenty of room for developing AVR and PSS furthermore in a effective and reliable way, pondering quite a lot of uncertainties that could appear while operating current power systems.