concentration vs focus

concentration and focus both are nouns.

Word	Noun	Adjective	Verb	Adverb
concentration	Yes	No	No	No
focus	Yes	No	Yes	No

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

Other hyponyms of concentration include centering, centring, direction, focal point, focusing, focussing, specialism, study.

concentration (noun)	focus (noun)
strengthening the concentration (as of a solute in a mixture) by removing diluting material	maximum clarity or distinctness of an image rendered by an optical system
bringing together military forces	maximum clarity or distinctness of an idea
great and constant diligence and attention	the concentration of attention or energy on something
the strength of a solution; number of molecules of a substance in a given volume	a fixed reference point on the concave side of a conic section
the spatial property of being crowded together	a point of convergence of light (or other radiation) or a point from which it diverges
complete attention; intense mental effort	a central point or locus of an infection in an organism
increase in density	special emphasis attached to something

concentration (verb)	focus (verb)
	become focussed or come into focus
	put (an image) into focus
	direct one's attention on something
	bring into focus or alignment; to converge or cause to converge; of ideas or emotions
	cause to converge on or toward a central point