Which one do I have?
Year and engine size will make this answer very easy.
All questions about timing belts or chains should be given a 6 month rest.
Find a mirror, and look at your waist, and at your neck.
Please let us know what you find out. 
BC.
I’ll bet your owners manual can answer that. Have you even looked, never mind I know you didn’t.
It depends on the S&M activity you are involved in.
That and any other thing that is covered in the owners manual.
If your maintenance schedule calls for a timing belt replacement at a specific mileage interval, you have a timing belt. If it does not, you have a timing chain. Being a Volkswagen Passat, you probably have a timing belt.
I agree with the others. These questions are getting kind of old.