This chapter presents a comprehensive overview of the cerebral cortex and subcortical structures, emphasizing their anatomical organization, functional localization, and clinical relevance. Following a general description of telencephalic organization and phylogenetic development, the functional architecture of the cerebral cortex is discussed based on Brodmann areas. The frontal lobe is examined in detail, including the primary and secondary motor cortices, motor homunculus, frontal eye field, motor speech area, and the role of the prefrontal cortex in cognitive and behavioral functions. The parietal lobe section addresses primary and secondary somatosensory cortices and their association areas involved in sensory integration. In the temporal lobe, the primary auditory cortex and Wernicke’s area are described, while the occipital lobe focuses on primary and secondary visual cortices. Subcortical structures, particularly the thalamus and subthalamus, are discussed in relation to their connections with cortical regions and their roles in motor and sensory modulation. Clinical correlations throughout the chapter highlight the neurological consequences of cortical and subcortical lesions, underscoring the clinical significance of functional localization.