join vs link

join and link both are nouns.

Word	Noun	Adjective	Verb	Adverb
join	Yes	No	Yes	No
link	Yes	No	Yes	No

As nouns, link is a hypernym of join; that is, link is a word with a broader meaning than join:

join: the shape or manner in which things come together and a connection is made
link: a connecting shape

Other hypernyms of join include connection, connexion.

As verbs, link is a hypernym of join; that is, link is a word with a broader meaning than join:

Other hypernyms of join include connect, link up, tie.

As verbs, link is a hypernym of join; that is, link is a word with a broader meaning than join:

Other hypernyms of join include connect, link up, tie.

As verbs, join and link are synonyms defined as:

Other synonyms of join include connect, link up, unite.

join (noun)	link (noun)
a set containing all and only the members of two or more given sets	a fastener that serves to join or connect
the shape or manner in which things come together and a connection is made	a two-way radio communication system (usually microwave); part of a more extensive telecommunication network
	an interconnecting circuit between two or more locations for the purpose of transmitting and receiving data
	a channel for communication between groups
	(computing) an instruction that connects one part of a program or an element on a list to another program or list
	a unit of length equal to 1/100 of a chain
	the means of connection between things linked in series
	a connecting shape
	the state of being connected

join (verb)	link (verb)
make contact or come together	make a logical or causal connection
cause to become joined or linked	connect, fasten, or put together two or more pieces
become part of; become a member of a group or organization	link with or as with a yoke
come into the company of	be or become joined or united or linked
be or become joined or united or linked