General usage:
* My occupation is software engineer.
* She listed her occupation as "student" on the application.
* The census asks about your occupation and income.
Referring to a specific job:
* The occupation of a doctor requires extensive training.
* The occupation of a firefighter is dangerous but rewarding.
* The occupation of a teacher is often undervalued.
Referring to an act of taking control:
* The invading army carried out the occupation of the city.
* The military occupation lasted for several years.
* The rebels staged a fierce resistance against the occupation forces.
With different meanings:
* The occupation of the house was quite peaceful. (meaning "inhabiting")
* The occupation of their time was filled with leisure activities. (meaning "what takes up their time")
* The occupation of the building by the protesters lasted for three days. (meaning "taking control of")
The meaning of "occupation" will be determined by the context of the sentence.