action vs process

action and process both are nouns.

Word	Noun	Adjective	Verb	Adverb
action	Yes	No	Yes	No
process	Yes	No	Yes	No

As nouns, process is a hypernym of action; that is, process is a word with a broader meaning than action:

action: a process existing in or produced by nature (rather than by the intent of human beings)
process: a sustained phenomenon or one marked by gradual changes through a series of states

Other hypernyms of action include physical process.

As verbs, action and process are synonyms defined as:

action and process: institute legal proceedings against; file a suit against

Other synonyms of action include litigate, sue.

action (noun)	process (noun)
the most important or interesting work or activity in a specific area or field	a sustained phenomenon or one marked by gradual changes through a series of states
a judicial proceeding brought by one party against another; one party prosecutes another for a wrong done or for protection of a right or for prevention of a wrong	a particular course of action intended to achieve a result
something done (usually as opposed to something said)	a natural prolongation or projection from a part of an organism either animal or plant
a military engagement	(psychology) the performance of some composite cognitive activity; an operation that affects mental contents
an act by a government body or supranational organization	a mental process that you are not directly aware of
the operating part that transmits power to a mechanism	a writ issued by authority of law; usually compels the defendant's attendance in a civil suit; failure to appear results in a default judgment against the defendant
In firearms terminology, the mechanism that handles the ammunition (loads, locks, fires, and extracts the cartridges).
the trait of being active and energetic and forceful
the series of events that form a plot
a process existing in or produced by nature (rather than by the intent of human beings)
the state of being active

action (verb)	process (verb)
put in effect	subject to a process or treatment, with the aim of readying for some purpose, improving, or remedying a condition
institute legal proceedings against; file a suit against	perform mathematical and logical operations on (data) according to programmed instructions in order to obtain the required information
	deliver a warrant or summons to someone
	shape, form, or improve a material
	institute legal proceedings against; file a suit against
	deal with in a routine way
	march in a procession