digging vs excavation

digging and excavation both are nouns.

Word	Noun	Adjective	Verb	Adverb
digging	Yes	No	No	No
excavation	Yes	No	No	No

As nouns, digging and excavation are synonyms defined as:

Other synonyms of digging include dig.

digging (noun)	excavation (noun)
the act of digging	the act of extracting ores or coal etc from the earth
	the act of digging
	a hole in the ground made by excavating
	the site of an archeological exploration