process vs operation

process and operation both are nouns.

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

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

process: a sustained phenomenon or one marked by gradual changes through a series of states
operation: process or manner of functioning or operating

As nouns, process and operation are synonyms defined as:

process and operation: (psychology) the performance of some composite cognitive activity; an operation that affects mental contents

Other synonyms of process include cognitive operation, cognitive process, mental process.

process (noun)	operation (noun)
a sustained phenomenon or one marked by gradual changes through a series of states	a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body
a particular course of action intended to achieve a result	(mathematics) calculation by mathematical methods
a natural prolongation or projection from a part of an organism either animal or plant	activity by a military or naval force (as a maneuver or campaign)
(psychology) the performance of some composite cognitive activity; an operation that affects mental contents	a planned activity involving many people performing various actions
a mental process that you are not directly aware of	a process or series of acts especially of a practical or mechanical nature involved in a particular form of work
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	a business especially one run on a large scale
	the activity of operating something (a machine or business etc.)
	(psychology) the performance of some composite cognitive activity; an operation that affects mental contents
	(computer science) data processing in which the result is completely specified by a rule (especially the processing that results from a single instruction)
	process or manner of functioning or operating
	the state of being in effect or being operative

process (verb)	operation (verb)
subject to a process or treatment, with the aim of readying for some purpose, improving, or remedying a condition
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