Nervous system : Difference between tract and nerve

Composition of nervous tissue :
1. neuron : excitable cell
2. Neuroglia : supporting cells
Parts of a neuron :

1. cell body 
2. processes : 2 in number 

i) dendrite: 1 or more than one in number

ii) Axon : usually one in number 

Axons are situated both CNS PNS
axon within the CNS is known as tract 
axons outside the CNS is known as nerve 

Topic                              Tract                                                 Nerve
location                          Mostly CNS                                   Part of PNS (peripheral NS)
myalination                     oligodendrocyte                           Schwann cells 
Type                   Ascending & descending tract    Sensory, motor and mixed both sensory& motor