Predictive processing is a theoretical framework in cognitive science, neuroscience, and philosophy of mind that posits the brain actively generates predictions about incoming sensory information. It investigates how the brain constructs an internal model of the world by continuously comparing these predictions against actual sensory input and updating its model based on the resulting discrepancies, known as prediction errors. This approach characterizes perception, cognition, and action as fundamentally driven by the minimization of such errors, offering a unified account of brain function.