White matter refers to the neural tissue within the brain and spinal cord that is predominantly made up of myelinated axons. Myelin is a fatty substance that surrounds and insulates nerve fibers, allowing for faster transmission of electrical signals between different areas of the brain. White matter plays a crucial role in facilitating communication between different regions of the brain and is essential for coordinating various functions such as movement, sensation, and cognition. Research in the area of white matter focuses on understanding its structure and function, as well as how abnormalities in white matter can contribute to neurological and psychiatric disorders such as multiple sclerosis, Alzheimer's disease, and schizophrenia. Advanced neuroimaging techniques such as diffusion tensor imaging (DTI) are commonly used to study white matter connectivity and integrity in the brain.