The axon is the primary method of information transmission for the nervous system. They bundle together to form nerves, which allow information to be transmitted over long distances. They can also serve as nerve tracts, which are bundles of axons that connect different regions of the brain and central nervous system.
Appearance
Axons are long, thin, and cylindrical. They are typically between 1 and 20 micrometers in diameter, but can be as large as 100 micrometers in diameter. They are typically much longer than Dendrites, and can be up to a meter long in some cases.
They vary in use case quite a bit, as some axons may just be a millimeter in length to other neurons, while others might extend from the brain all the way down the spinal cord.