The cerebrum (Latin for brain), refers to the part of the brain comprising the cerebral cortex (in the two cerebral hemispheres), as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In humans, the cerebrum is the superior-most region of the central nervous system (CNS). However, in nearly all other vertebrates, the cerebrum is the anterior-most region of the CNS as most animals rarely assume an upright anatomical position. The telencephalon refers to the embryonic structure from which the mature cerebrum develops. In mammals, the dorsal telencephalon, or pallium, develops into the cerebral cortex, and the ventral telencephalon, or subpallium, becomes the basal ganglia. The cerebrum is also divided into approximately symmetric left and right cerebral hemispheres.

The cerebrum, which develops from the front portion of the forebrain, is the largest part of the mature brain. It consists of two large masses, called cerebral hemispheres, which are almost mirror images of each other. They are connected by a deep bridge of nerve fibers called the corpus callosum and are separated by a layer called the falx cerebri. The surface of the cerebrum is marked by numerous ridges or convolutions, called gyri, which are also separated by grooves. A shallow groove is called a sulcus, and a very deep one is a fissure. A longitudinal fissure separates the right and left hemispheres of the cerebrum, and a transverse fissure separates the cerebrum from the cerebellum. Various sulci divide each hemisphere into lobes (sometimes called poles). The lobes are named for the skull bones under which they rest and are: (1) the frontal lobe, (2) the parietal lobe, (3) the temporal lobe, (4) the occipital lobe, and (5) the insula. The cerebrum is concerned with higher brain functions, interpreting sensory impulses and initiating muscle movements. It stores information and uses it to process reasoning. It also functions in determining intelligence and personality.