<p>This paper provides a review of various state estimation methods and their techniques in power systems. State estimation is a technique employed to ensure a reliable and accurate representation of power system parameters, such as voltage, current, phase angle, active power, and reactive power, regardless of potential measurement errors. It estimates state variables of the power system based on measurements made across the network while also ensuring that these estimates comply with the measurements. It is particularly useful for ensuring system security by identifying bad measurements, determining the line power flows among the buses, and addressing restrictions related to economic dispatch. This paper discusses the different types of state estimation based on factors such as nature, network, and type of supply. Additionally, this study conducts a comprehensive review and analysis of conventional state estimation techniques and challenges in identifying bad data and subsequently provides a brief summary of their respective merits and limitations.</p>