tagger vs tagging program

tagger and tagging program both are nouns.

Word	Noun	Adjective	Verb	Adverb
tagger	Yes	No	No	No
tagging program	Yes	No	No	No

As nouns, tagger and tagging program are synonyms defined as:

tagger and tagging program: a computer program that attaches labels to the grammatical constituents of textual matter

tagger (noun)	tagging program (noun)
a computer program that attaches labels to the grammatical constituents of textual matter	a computer program that attaches labels to the grammatical constituents of textual matter
someone who appends or joins one thing to another
someone who assigns labels to the grammatical constituents of textual matter