handler vs conditioner

handler and conditioner both are nouns.

Word	Noun	Adjective	Verb	Adverb
handler	Yes	No	No	No
conditioner	Yes	No	No	No

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

handler (noun)	conditioner (noun)
(sports) someone in charge of training an athlete or a team	exercise that conditions the body
one who trains or exhibits animals	a substance used in washing (clothing or hair) to make things softer
an agent who handles something or someone	a trainer of athletes