transition vs segue

transition and segue both are nouns.

Word	Noun	Adjective	Verb	Adverb
transition	Yes	No	Yes	No
segue	Yes	No	Yes	No

As nouns, segue is a hyponym of transition; that is, segue is a word with a more specific, narrower meaning than transition:

Other hyponyms of transition include fossilisation, fossilization.

transition (noun)	segue (noun)
the act of passing from one state or place to the next	the act of changing smoothly from one state or situation to another
a passage that connects a topic to one that follows
a musical passage moving from one key to another
an event that results in a transformation
a change from one place or state or subject or stage to another

transition (verb)	segue (verb)
make or undergo a transition (from one state or system to another)	proceed without interruption; in music or talk
cause to convert or undergo a transition