attach vs link up

attach and link up both are verbs.

Word	Noun	Adjective	Verb	Adverb
attach	No	No	Yes	No
link up	No	No	Yes	No

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

Other hypernyms of attach include connect, link, tie.

attach (verb)	link up (verb)
become attached	make a logical or causal connection
cause to be attached	connect, fasten, or put together two or more pieces
be attached; be in contact with	be or become joined or united or linked
take temporary possession of as a security, by legal authority
create social or emotional ties