sum vs coverage

sum and coverage both are nouns.

Word	Noun	Adjective	Verb	Adverb
sum	Yes	No	Yes	No
coverage	Yes	No	No	No

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

sum (noun)	coverage (noun)
the whole amount	the extent to which something is covered
the choicest or most essential or most vital part of some idea or experience	the news as presented by reporters for newspapers or radio or television
a quantity obtained by the addition of a group of numbers	the total amount and type of insurance carried
the final aggregate
a set containing all and only the members of two or more given sets
a quantity of money

sum (verb)	coverage (verb)
determine the sum of
be a summary of