Axons are the long slender extensions of neurons that transmit signals along their length away from the central body of the neuron. Axons terminate and pass signals to muscles, glands and dendrites through a synapse. Each neuron only has one axon, which is typically much longer than the central cell body. Certain types of axons can pass signals in opposite directions down different branches. Nerves are made of bundles of axons.
Axons may or may not be coated in myelin. Those coated in myelin can transmit signals at a much higher speed than unmyelinated axons. However, the part of the axon next to the cell body is never covered in myelin. Most myelin coated axons still have gaps which allow the signal to propagate along other axons.