function vs computer software

function and computer software both are nouns.

Word	Noun	Adjective	Verb	Adverb
function	Yes	No	Yes	No
computer software	Yes	No	No	No

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

function: a set sequence of steps, part of larger computer program
computer software: (computer science) written programs or procedures or rules and associated documentation pertaining to the operation of a computer system and that are stored in read/write memory

Other hypernyms of function include package, software, software package, software program, software system.

function (noun)	computer software (noun)
the actions and activities assigned to or required or expected of a person or group	(computer science) written programs or procedures or rules and associated documentation pertaining to the operation of a computer system and that are stored in read/write memory
what something is used for
a set sequence of steps, part of larger computer program
a formal or official social gathering or ceremony of people
a formal or official social gathering or ceremony
(mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)
a relation such that one thing is dependent on another

function (verb)	computer software (verb)
perform duties attached to a particular office or place or function
perform as expected when applied
serve a purpose, role, or function