This review discusses random walk models in biology, focusing on their mathematical foundations and applications in understanding animal and cell movement. Random walks, originally derived from Brownian motion, are used to model movement in various biological contexts, including animal dispersal, cell migration, and chemotaxis. The paper introduces the basic theory of random walks, including unbiased (isotropic) and biased (drifted) models, as well as correlated random walks (CRWs) and biased correlated random walks (BCRWs). It explains how these models can be extended to include drift, waiting times, and first passage times. The paper also covers the application of random walks in modeling animal and cell movement, including chemotaxis and angiogenesis. It discusses the relationship between different random walk models and their relevance to biological processes, highlighting the importance of understanding diffusion, dispersal, and navigation in biological systems. The paper emphasizes the use of random walk models to predict movement patterns, dispersal distances, and tortuosity, while also addressing the limitations of these models. It concludes by discussing the connections between different random walk models and their role in understanding key biological processes.This review discusses random walk models in biology, focusing on their mathematical foundations and applications in understanding animal and cell movement. Random walks, originally derived from Brownian motion, are used to model movement in various biological contexts, including animal dispersal, cell migration, and chemotaxis. The paper introduces the basic theory of random walks, including unbiased (isotropic) and biased (drifted) models, as well as correlated random walks (CRWs) and biased correlated random walks (BCRWs). It explains how these models can be extended to include drift, waiting times, and first passage times. The paper also covers the application of random walks in modeling animal and cell movement, including chemotaxis and angiogenesis. It discusses the relationship between different random walk models and their relevance to biological processes, highlighting the importance of understanding diffusion, dispersal, and navigation in biological systems. The paper emphasizes the use of random walk models to predict movement patterns, dispersal distances, and tortuosity, while also addressing the limitations of these models. It concludes by discussing the connections between different random walk models and their role in understanding key biological processes.