Should I store the parent and child in a row or only the child

Question

Let's say I'm building a car rentals application, and at a point I have to show all available cars.

In the DB, I have the following tables:

• Brand
• Model
• Cars

In Model, there is a FK to Brand, let's say Brand_id

So my question is:

Cars table should have Brand and Model columns? Or only a Model column given that I could get the Brand from the Model column?