Beginner question: What do the terms 'driven' and 'driving' mean?

In short:

- a driving dimension will change the geometry of the model  (like when you ask your foreman in real life to "make this bar 3" long").

- a driven dimension will only measure an existing model without affecting it ("please check this bar and tell me how long it is").

or

- a driving dimension drives the model (change the dimension => change the model)

- a driven or reference dimension is driven by the model (change the model => change the dimension)