Myelinated nerve fibers are specialized nerve cells that have a protective covering called myelin. This myelin sheath is made up of oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. The myelin acts as an insulator, allowing electrical signals to travel more quickly along the nerve fibers. These fibers are crucial for efficient communication within the nervous system. The myelin sheath is not continuous; it has gaps called Nodes of Ranvier. These nodes enable the electrical impulses to jump from one node to another, significantly speeding up signal transmission compared to unmyelinated fibers.