Non-linear oscillators are systems that exhibit oscillatory behavior but do not follow a straight-line relationship between force and displacement. Unlike linear oscillators, where the restoring force is directly proportional to displacement, non-linear oscillators can have more complex relationships, leading to varied and unpredictable motion. Examples include pendulums with large swings and spring systems with non-linear stiffness. These oscillators can display phenomena such as bifurcations, where small changes in parameters lead to sudden shifts in behavior, and chaos, where the system becomes highly sensitive to initial conditions. Non-linear oscillators are found in many natural and engineered systems, including electronic circuits and biological rhythms.