Bell nonlocality refers to the phenomenon where quantum mechanics predicts correlations between distant particles that cannot be explained by any local theory. This concept, introduced by Bell in 1964, has become a central topic in quantum information science. The review discusses the mathematical characterization of nonlocal correlations, including no-signaling, local, and quantum correlations, and explores their implications for quantum theory and applications. It covers Bell inequalities, which are linear constraints on probabilities that must be satisfied by local theories but can be violated by quantum mechanics. The review also addresses multipartite nonlocality, experimental aspects of Bell tests, and the information-theoretic perspective on nonlocality. It highlights the importance of nonlocality in quantum information protocols, such as quantum cryptography and communication complexity, and discusses the challenges of experimental verification, including loopholes in Bell tests. The review concludes with a discussion of related concepts and the broader implications of nonlocality in physics.Bell nonlocality refers to the phenomenon where quantum mechanics predicts correlations between distant particles that cannot be explained by any local theory. This concept, introduced by Bell in 1964, has become a central topic in quantum information science. The review discusses the mathematical characterization of nonlocal correlations, including no-signaling, local, and quantum correlations, and explores their implications for quantum theory and applications. It covers Bell inequalities, which are linear constraints on probabilities that must be satisfied by local theories but can be violated by quantum mechanics. The review also addresses multipartite nonlocality, experimental aspects of Bell tests, and the information-theoretic perspective on nonlocality. It highlights the importance of nonlocality in quantum information protocols, such as quantum cryptography and communication complexity, and discusses the challenges of experimental verification, including loopholes in Bell tests. The review concludes with a discussion of related concepts and the broader implications of nonlocality in physics.