Hypocrisy is not following a principle while telling someone else that they did not follow a principle.[1][2] The person who does hypocrisy may not necessarily know that he is not following the principle.[3]
A hypocrite is a person who does hypocrisy. A person who is a hypocrite will criticize at someone else not to do a certain behavior or activity but still do the same behavior or activity. For example, if Person A shouted at Person B that Person B should not talk loudly, then Person A is a hypocrite.