When I create a new property, Google Analytics asks for a "Default URL". GA then creates a profile by default, with a "Website's URL" field that contains the URL I introduced previously on the property.
So far so good.
Now I find that I can change each one separately:
On property settings -> Default URL
On profile settings -> Website's URL
So, what I'm missing here is, how does GA exactly use these two fields, and what happens if I write different URLs in them?