What is coax?
If you are using the cobber net (ADSL) you need a broadband plug to be able to watch TV. The opposite of coax.
For most people in Denmark it does matter whether they get broadband via coax or the fiber network.
What is the fiber network?
The fiber network is contrary to normal broadband in Denmark delivered with fiber optic cables. A normal broadband connection is delivered via cobber and therefore the fiber network can provide substantially faster broadband.