This book introduces the classical three-body problem, highlighting its complexity, non-integrability, and relevance in celestial mechanics. Discusses types of three-body systems and basic solution approaches. Applies the restricted three-body model to analyze the Moon's motion under the gravitational influence of Earth and the Sun, including effects like orbital perturbations and tidal interactions. This book explores temporary interactions among three bodies, focusing on scattering, capture, and escape phenomena. Describes chaotic behavior and energy exchanges during close encounters. Analyzes how binaries interact with a third body, leading to outcomes like binary disruption, exchange, or tightening. Crucial in stellar dynamics and compact object interactions. Examines how giant molecular clouds gravitationally perturb Oort Cloud comets, triggering inward migration and potential comet showers in the solar system.