A wireless router connects (usually) to an incoming telephone line. It communicates with your computer either by wireless signals or by a piece of cable (hard wired) and you can swap from one to the other at will.
Wireless connectivity is particularly useful if you have a laptop and operate it at different places in the house or garden. I sometimes take my wireless laptop to the garage.
If your house is an electrically noisy environment the connection speed to your router will be faster with a cable - wireless will suffer to a greater or lesser extent - probably not much - you will find it difficult to notice much difference.
Most (all?) wireless routers have the capability to connect with a wire - they can handle multiple wireless connections and several (4) cable connections AT THE SAME TIME.
So just get yourself a wireless router and connect up.
Out of interest (it may be of interest to you) My Internet Service Provider is BT and we use a BT supplied router - should there ever be a problem (about once per year) there is no dispute about who to blame - it will always be down to BT and this makes our life a bit easier.
I think your question Which is Best? hardly arises - I would guess that all connection offerings have both cable and wireless capability.
Good Luck..
August 2015