Artificial Intelligence is the broader concept of machines being able to carry out tasks in a way that we would consider "smart". According to Stanford Researcher, John McCarthy, "Artificial Intelligence is the science and engineering of making intelligent machines, especially intelligent computer programs. Artificial Intelligence is related to the similar task of using computers to understand human intelligence, but AI does not have to confine itself to methods that are biologically observable." Simply put, AI's goal is to make computers/computer programs smart enough to imitate the human mind behaviour. Knowledge Engineering is an essential part of AI research.