Occupation is about the money. Vocation is never about the money. Occupation is what the market values. Vocation is what God values. Occupation can be downsized, out-sourced, laid off, hired, fired or retired.
Vocation is for life.
Occupation is what you create for yourself. Vocation is what you were created for. The problem is to find out which is the voice of God rather than of Society, say, or the Superego, or Self-Interest. That's not a multiple-choice question on a job application, graduates. That's an essay you write with your life.