This paper introduces the concept of quantum steering, a generalization of the EPR paradox for arbitrary pure bipartite entangled states and arbitrary measurements by one party. It provides an operational definition of steering and proves that steerable states are a strict subset of entangled states and a strict superset of Bell-nonlocal states. The paper also relates steering to the original EPR paradox and discusses the hierarchy of quantum nonlocality, nonseparability, and steerability. Steering is defined as the ability of one party (Alice) to affect the state of another party (Bob) through her choice of measurement basis. This is distinct from Bell-nonlocality, which involves correlations that cannot be explained by local hidden variable models. The paper shows that steerability is stronger than nonseparability but weaker than Bell-nonlocality. It also proves that not all entangled states are steerable, and not all steerable states are Bell-nonlocal. The paper analyzes three families of states: Werner states, Isotropic states, and Gaussian states. For Werner states, it shows that steerability is strictly weaker than Bell-nonlocality. For Isotropic states, it determines the threshold for steerability in terms of a harmonic series. For Gaussian states, it derives a linear matrix inequality that determines steerability under Gaussian measurements. The paper also discusses the relationship between steering and the EPR paradox, showing that the EPR paradox is a particular case of steering. It concludes with a discussion of open questions, including whether asymmetric states can be steered by one party but not the other, and whether steering has applications beyond the defining task. The paper highlights the importance of steering in quantum information theory and experimental quantum information.This paper introduces the concept of quantum steering, a generalization of the EPR paradox for arbitrary pure bipartite entangled states and arbitrary measurements by one party. It provides an operational definition of steering and proves that steerable states are a strict subset of entangled states and a strict superset of Bell-nonlocal states. The paper also relates steering to the original EPR paradox and discusses the hierarchy of quantum nonlocality, nonseparability, and steerability. Steering is defined as the ability of one party (Alice) to affect the state of another party (Bob) through her choice of measurement basis. This is distinct from Bell-nonlocality, which involves correlations that cannot be explained by local hidden variable models. The paper shows that steerability is stronger than nonseparability but weaker than Bell-nonlocality. It also proves that not all entangled states are steerable, and not all steerable states are Bell-nonlocal. The paper analyzes three families of states: Werner states, Isotropic states, and Gaussian states. For Werner states, it shows that steerability is strictly weaker than Bell-nonlocality. For Isotropic states, it determines the threshold for steerability in terms of a harmonic series. For Gaussian states, it derives a linear matrix inequality that determines steerability under Gaussian measurements. The paper also discusses the relationship between steering and the EPR paradox, showing that the EPR paradox is a particular case of steering. It concludes with a discussion of open questions, including whether asymmetric states can be steered by one party but not the other, and whether steering has applications beyond the defining task. The paper highlights the importance of steering in quantum information theory and experimental quantum information.