immersion vs focussing

immersion and focussing both are nouns.

Word	Noun	Adjective	Verb	Adverb
immersion	Yes	No	No	No
focussing	Yes	No	No	No

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

Other hyponyms of immersion include centering, centring, direction, focal point, focus, focusing, specialism, study.

immersion (noun)	focussing (noun)
a form of baptism in which part or all of a person's body is submerged	the concentration of attention or energy on something
the act of wetting something by submerging it
complete attention; intense mental effort
sinking until covered completely with water
(astronomy) the disappearance of a celestial body prior to an eclipse