One of the great uncertainties in today's society is how to replace current energy sources with others that provide comparable or greater output while being sustainable and supporting global decarbonization goals. One of the alternatives postulated as a solution is nuclear fusion, as it is a source of energy that is considered clean and that works with fuel that is in abundance. Therefore, the main objective of this paper is to make a review on the current state of knowledge of the different and most developed reactor configurations (Tokamak, Stellarator and Inertial Confinement fusion laser) that exist to date, making a comparative analysis between them, in which the differences and opportunities of each one can be glimpsed. It will also be possible to identify the challenges that concern such energy and to propose possible solutions to them. The results determined how the ICF reactors obtain better energy results with efficiencies of around 35%, while the Tokamak and Stellarator obtain values of around 31%. Also, the findings stated that the construction of such reactors needs enormous investments, being the cheapest the Stellarator, reaching construction values of around $2 billion. It has to be mentioned that the results and calculations that have been made to make especially the cost estimation, are based on estimates and assumptions due to the complexity and lack of evidence of such energy, so they can be considered as approximate outcomes. However, these results are fully valid and follow rational considerations and estimates that give an idea of the current state of these technologies. In summary, the thesis provided an overview of the current state of fusion and outline the potential challenges and the impact that it will have in the coming years.