preoccupation vs occupation

preoccupation and occupation both are nouns.

Word	Noun	Adjective	Verb	Adverb
preoccupation	Yes	No	No	No
occupation	Yes	No	No	No

As nouns, occupation is a hypernym of preoccupation; that is, occupation is a word with a broader meaning than preoccupation:

Other hypernyms of preoccupation include moving in, occupancy.

preoccupation (noun)	occupation (noun)
the act of taking occupancy before someone else does	the principal activity in your life that you do to earn money
the mental state of being preoccupied by something	the act of occupying or taking possession of a building
an idea that preoccupies the mind and holds the attention	the control of a country by military forces of a foreign power
	any activity that occupies a person's attention
	the period of time during which a place or position or nation is occupied