Facts are both data and "source code". It's a fact that a user with id=0 has name=Bob. It's also a fact that the sqrt(x^2)=x or the http response code when a re

Facts are both data and "source code". It's a fact that a user with id=0 has name=Bob. It's also a fact that the sqrt(x^2)=x or the http response code when a resource isn't found is 404. Some of those belong in databases, some definitely don't.