item vs component

item and component both are nouns.

Word	Noun	Adjective	Verb	Adverb
item	Yes	No	No	Yes
component	Yes	No	No	No

As nouns, component is a hypernym of item; that is, component is a word with a broader meaning than item:

item: a distinct part that can be specified separately in a group of things that could be enumerated on a list
component: something determined in relation to something that includes it

Other hypernyms of item include component part, constituent, part, portion.

As nouns, component is a hypernym of item; that is, component is a word with a broader meaning than item:

Other hypernyms of item include component part, constituent, part, portion.

item (noun)	component (noun)
a whole individual unit; especially when included in a list or collection	an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system
an isolated fact that is considered separately from the whole	an abstract part of something
a distinct part that can be specified separately in a group of things that could be enumerated on a list	something determined in relation to something that includes it
an individual instance of a type of symbol
a small part that can be considered separately from the whole

item (adverb)	component (adverb)
(used when listing or enumerating items) also