observe vs keep tabs on

observe and keep tabs on both are verbs.

Word	Noun	Adjective	Verb	Adverb
observe	No	No	Yes	No
keep tabs on	No	No	Yes	No

As verbs, keep tabs on is a hyponym of observe; that is, keep tabs on is a word with a more specific, narrower meaning than observe:

Other hyponyms of observe include guard, invigilate, proctor.

observe (verb)	keep tabs on (verb)
stick to correctly or closely	keep a record on or watch attentively
make mention of
watch attentively
observe with care or pay close attention to
discover or determine the existence, presence, or fact of by perception with the eyes
follow with the eyes or the mind
show respect towards
behave as expected during of holidays or rites
conform one's action or practice to