trailing vs tracking

trailing and tracking both are nouns.

Word	Noun	Adjective	Verb	Adverb
trailing	Yes	No	No	No
tracking	Yes	No	No	No

As nouns, trailing and tracking are synonyms defined as:

trailing and tracking: the pursuit (of a person or animal) by following tracks or marks they left behind

trailing (noun)	tracking (noun)
the pursuit (of a person or animal) by following tracks or marks they left behind	the pursuit (of a person or animal) by following tracks or marks they left behind