trial run vs alpha test

trial run and alpha test both are nouns.

Word	Noun	Adjective	Verb	Adverb
trial run	Yes	No	No	No
alpha test	Yes	No	No	No

As nouns, alpha test is a hyponym of trial run; that is, alpha test is a word with a more specific, narrower meaning than trial run:

trial run: trying something to find out about it
alpha test: (computer science) a first test of an experimental product (such as computer software) carried out by the developer

Other hyponyms of trial run include field test, field trial, beta test, road test, trial balloon.

trial run (noun)	alpha test (noun)
trying something to find out about it	(computer science) a first test of an experimental product (such as computer software) carried out by the developer