The striatum is the largest component of the basal ganglia.
It consists chiefly of the caudate nucleus and putamen, which are often grouped together because they share developmental origins and receive major inputs from the cerebral cortex. The striatum helps select and scale movements, but it also participates in learning, motivation, and habit formation.
The basal ganglia are a set of interconnected deep-brain nuclei rather than a single structure. Their circuits influence movement indirectly through loops involving the cortex, thalamus, and brainstem. The globus pallidus, subthalamic nucleus, and substantia nigra are other important components.
A frequent mix-up is treating the striatum as identical to the entire basal ganglia. The term “striatum” refers specifically to a major input region, while the broader basal-ganglia system includes several nuclei with different circuit roles. In anatomy, the caudate and putamen are separated anteriorly but connected by bridges of gray matter, creating the striped appearance that inspired the name.