This article provides an overview of the anatomical and neurochemical components of the basal ganglia, its historical development, and its involvement in various neurological and psychiatric disorders. The basal ganglia's intricate circuitry, involving the striatum, globus pallidus, substantia nigra, and subthalamic nucleus, is discussed, emphasizing its role in action selection and motor control. The historical journey from early anatomical observations to modern neuroscience techniques is traced, highlighting key contributors and breakthroughs. The article delves into the cortico-basal ganglia-thalamo-cortical loop, the direct and indirect pathways, and the modulation of basal ganglia activity by dopamine. A detailed analysis of the basal ganglia's involvement in Parkinson's disease and Huntington's disease is provided, elucidating the disruptions in circuit connections leading to characteristic motor and cognitive symptoms. Overall, this comprehensive exploration enhances our understanding of the basal ganglia's intricate workings and its significance in health and disease