A paradox is a statement or situation that is at least seemingly contradictory (lying when put together).
Also paradoxes are more than one paradox.
Here is an interesting paradox
This sentence can never be true.
Since the sentence
This sentence can never be true
is warning it can never be true that makes the sentence
This sentence can never be true
a false sentence.
But since the sentence
This sentence is can never be true
is a false sentence that means it is lying and therefore a true sentence.
But since the sentence
This sentence can never be true
is telling the true then it is a false sentence.
Pretty cool huh?