central vs focal

central is a noun but focal is not a noun.

Word	Noun	Adjective	Verb	Adverb
central	Yes	Yes	No	No
focal	No	Yes	No	No

central (noun)	focal (noun)
a workplace that serves as a telecommunications facility where lines from telephones can be connected together to permit communication

central (adjective)	focal (adjective)
in or near a center or constituting a center; the inner area	of or relating to a focus
serving as an essential component	having or localized centrally at a focus