Definition of "Fact" :

noun: a piece of information about circumstances that exist or events that have occurred

"First you must collect all the facts of the case."

noun: a concept whose truth can be proved

"Scientific hypotheses are not facts."

noun: a statement or assertion of verified information about something that is the case or has happened

"He supported his argument with an impressive array of facts."

noun: an event known to have happened or something known to have existed

"Your fears have no basis in fact."