Publisher Summary This chapter presents the basic structures and regions of the brain and their function in human cognition. Brain has developed and changed through time and so some areas of the brain are older than others. The cortex or neocortex represents recent brain developments in the human, and the frontal and parietal lobes expand their neural territory tremendously as compared to non-human primates. While there are separable regions and parts of the brain, such as the two hemispheres and the four major lobes, nonetheless, the brain is highly interconnected with an extensive fiber pathway system that connects the hemispheres, the lobes, and provides circuits to subcortical regions. There are also some ancient regions, such as the reticular formation, that seem to play a key role in consciousness.