Vocation is what you do for the living. Occupation can get you things. Vocation can save you from things. 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.