mechanism vs paywall

mechanism and paywall both are nouns.

Word	Noun	Adjective	Verb	Adverb
mechanism	Yes	No	No	No
paywall	Yes	No	No	No

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

mechanism (noun)	paywall (noun)
the technical aspects of doing something	A mechanism used to limit access to only paying users
device consisting of a piece of machinery; has moving parts that perform some function
(philosophy) the philosophical theory that all phenomena can be explained in terms of physical or biological causes
a natural object resembling a machine in structure or function
the atomic process that occurs during a chemical reaction