runtime error vs software error

runtime error and software error both are nouns.

Word	Noun	Adjective	Verb	Adverb
runtime error	Yes	No	No	No
software error	Yes	No	No	No

As nouns, software error is a hypernym of runtime error; that is, software error is a word with a broader meaning than runtime error:

runtime error: an error in logic or arithmetic that must be detected at run time
software error: error resulting from bad code in some program involved in producing the erroneous result

Other hypernyms of runtime error include programming error.

runtime error (noun)	software error (noun)
an error in logic or arithmetic that must be detected at run time	error resulting from bad code in some program involved in producing the erroneous result