taxation vs direct tax

taxation and direct tax both are nouns.

Word	Noun	Adjective	Verb	Adverb
taxation	Yes	No	No	No
direct tax	Yes	No	No	No

As nouns, direct tax is a hyponym of taxation; that is, direct tax is a word with a more specific, narrower meaning than taxation:

taxation: charge against a citizen's person or property or activity for the support of government
direct tax: a tax paid directly by the person or organization on whom it is levied

taxation (noun)	direct tax (noun)
the imposition of taxes; the practice of the government in levying taxes on the subjects of a state	a tax paid directly by the person or organization on whom it is levied
charge against a citizen's person or property or activity for the support of government
government income due to taxation