Do you believe the Earth is FLAT or ROUND?

I have seen many conspiracy post's online and on social media depicting that the Earth is Flat and looks like this model:
Now I do not know much about it but from the little I have seen, most suggest Earth is a firmament as described in the Bible and that it is surrounded by ice that holds the water in. They imply that there is a dome and if that is the case, then space is fake and there is indeed a creator.

While most of the population believes the Earth is round and looks like this:

NASA has confirmed that they use illustrations to show Earth but are all pictures just illustrations?

Flat Earth Conspirators use this picture to debunk NASA's claims and tarnish their credibility:

So the question, is Earth really round, or flat? And why does it matter? What is YOUR opinion?