A fallacy is a type of argument that may seem to be correct, but that proves on examination not to be so.
Fallacies of relevance
In these fallacies, the premises of the argument are simply not relevant to the conclusion.
Fallacies of defective induction
In fallacies of defective induction, the premises may be relevant to the conclusion, but they are far too weak to support the conclusion.
Fallacies of presumption
In fallacies of presumption, the mistake in argument arises from relying on some proposition that is assumed to be true but is without warrant and is false or dubious.
Fallacies of ambiguity
In fallacies of ambiguity, the mistake in argument arise as a result of the shift in the meaning of words or phrases, from the meanings that they have in the premises to different meanings that they have in the conclusion.