Fact is the following:
- Generally a fact is an event that has happened, or a statement that is true in some objective sense — whether one accepts it as real (or true) or not. Sometimes, of course, there are differences of opinion over what is factual, and there are some methods for attempting to minimize those differences.
- In philosophy, a fact is either a true proposition or something (a state of affairs, for example) that "makes" a proposition true. (See truthmaker)
- In science, a fact is data supported by a scientific experiment. A fact is an honest observation. A scientific fact is an honest observation seen by many scientists. A scientific fact is a scientific observation that is so accepted that it becomes difficult to consider other interpretations of the data. A fact may tentatively support or refute a model of how the universe works. Facts do not prove a model is correct. One observation of any phenomenon does not prove anything. We tend to see facts which support our position and ignore facts which contradict our opinion. If we have power we feel justified in making the other guy experience our Truth.
- In law, a fact is a statement which is found to be true by a "tryer of fact," sometimes a jury, but often the court (the judge or judges) after hearing evidence.
- In computer science a fact is a single data value generated or used by a business process.
Facts are necessary as evidence to support empirical theories.