A random walk is significant in various fields, including physics, economics, and computer science, particularly in algorithms and AI for modeling randomness in processes. It's a stochastic or random process that describes a path that consists of a series of random steps on a space such as the integers, a grid, or more complex structures like networks. In AI, random walks are used in algorithms to solve optimization problems, model natural processes, and in machine learning for exploring the state space of models, among other applications. Its properties, like the expected distance from the start point and the likelihood of returning to the starting point, are studied to understand and predict the behavior of complex systems and processes.

Historical overview: The concept of a random walk was first introduced in the late 19th to early 20th century. It gained significant popularity in the 20th century as mathematicians and scientists began to formalize and apply it to problems in physics, economics, and the emerging field of computer science.

Key contributors: Notable figures in the development of random walk theory include George Pólya, who made significant contributions to the understanding of random walks on the lattice, particularly with his work on the probability of a random walk returning to its starting point in a finite number of steps.