Glial cells are cells that surround neurons and hold them in place, supply nutrients and oxygen to neurons, insulate neurons from one another, and remove dead neurons in the brain, central and peripheral nervous systems.
Glial cells include astrocytes (star-shaped cells that provide physical and nutritional support for neurons), microglia (digest parts of dead neurons), oligodendroglia (provides myelin to neurons in the central nervous system), satellite cells (physical support to neurons in the peripheral nervous system), and Schwann cells (provide myelin to neurons in the peripheral nervous system).