A fact is perhaps best described as a factual statement + truth. Facts are generally held to be mind-independent, i.e. they would continue to be the case whether or not anyone believed them, or indeed whether or not there were any minds to believe them in the first place.
A factual statement has a truth value, that is to say it is capable of being true or false. Not all statements are of this form, as we can see below:
1. Table salt is comprised of sodium and chlorine.
2. Table salt is comprised of zinc and chlorine.
3. The Beatles were great.
4. The Beatles were rubbish.
Statements 1 & 2 clearly have truth values of T & F respectively. We can therefore assert statement 1 as a fact. In the unlikely case of disagreement, there would be a straighforward recourse to direct experimental proof.
Statements 3 & 4, however, are more problematic. Whatever the weight of support for either side, there remains the possibility of two optimally informed and impartial judges failing to agree (see cognitive command). Without recourse to any direct method of proof, neither statement can be said to have a truth value and thus neither can be asserted as a fact.