As the world of technology continues to evolve, innovations and programs are integrated into the societal problems that the world is facing today. As robotics has opened a new chapter in the world of technology, there are so many ways to integrate this innovation and develop it to help solve the social and economic issues occurring, This paper emphasizes on how significant Autonomous Underwater Vehicles are in this world today as it aids in marine monitoring which can help in discoveries and marine protection. This paper also focuses on the function, system, and significant features of an Autonomous Underwater Vehicle. For the function the brief and most basic materials and software to develop the body of the device is studied, the system and process of data acquisition are covered, and the new and probable improvements that can be done shortly are also included in this paper. This study aims to establish the fundamental knowledge, the main functions, and the system of an Autonomous Underwater Vehicle.