unit vs segment

unit and segment both are nouns.

Word	Noun	Adjective	Verb	Adverb
unit	Yes	No	No	No
segment	Yes	No	Yes	No

unit (noun)	segment (noun)
an assemblage of parts that is regarded as a single entity	one of several parts or pieces that fit with others to constitute a whole object
a single undivided whole	one of the parts into which something naturally divides
an organization regarded as part of a larger social group
a single undivided natural thing occurring in the composition of something else
any division of quantity accepted as a standard of measurement or exchange
an individual or group or structure or other entity regarded as a structural or functional constituent of a whole

unit (verb)	segment (verb)
	divide into segments
	divide or split up