What is the largest major division of the human brain?

The cerebrum is the largest major division of the human brain.

It consists of two cerebral hemispheres joined by deep nerve-fibre pathways, including the corpus callosum. Its folded outer layer, the cerebral cortex, supports complex functions such as conscious perception, voluntary movement, language, reasoning, and memory. The grooves and ridges of the cortex increase its surface area within the skull.

The cerebrum is often confused with the entire brain. The brain also includes structures such as the cerebellum, brainstem, and diencephalon. In everyday language, however, “cerebrum” usually refers to the large paired cerebral mass that dominates the upper part of the brain.

Each hemisphere is commonly divided into frontal, parietal, temporal, and occipital lobes, although functional boundaries are more complicated than those four labels suggest. The cerebrum is therefore both an anatomical division and the main site of many higher cognitive activities.