Artificial Intelligence is the concept of computer science which deals with building computers that exhibits the intelligent behaviour like us. In other words it concern with making intelligent machines which having ability of learning something, problem solving and understanding of language. These machines are called intelligent agent. This all can be done with the help of expert system. The paper briefs about what AI exactly means, why we need it, its application, future phases, advantages and some of disadvantages. This technology is user-friendly, smarter, and sensitive. Also makes our work easier. We use it in making of robots and robots are used in various fields for various purposes. This technology is answerable of some critical questions about human existence by understanding the nature of intelligence, but this all happen scientifically and technically by affecting many aspects of society and culture.