A long, slender projection from the nerve cells is called a nerve fiber or axon.
Axon is responsible for conducting electrical impulses called action potential away from the nerve cell body.
Types of nerve fibers found in PNS:
Efferent nerve-fibers: The nerve fibers which carry electrical impulses away from the central nervous system are called efferent nerve fibers or motor fibers.
Afferent nerve fibers: The nerve fibers which carry electrical impulses toward the central nervous system are called afferent nerve fibers.