If you are looking for an answer to the question What is Artificial Intelligence? and you only have a minute, then here's the definition the Association for the Advancement of Artificial Intelligence offers on its home page: "the scientific understanding of the mechanisms underlying thought and intelligent behavior and their embodiment in machines."
However, if you are fortunate enough to have more than a minute, then please get ready to embark upon an exciting journey exploring AI (but beware, it could last a lifetime) …
... the technique of heuristic programmingis under detailed investigation as a means to the end of applying largescaledigital computers to the solution of a difficult class of problems currentlyconsidered to be beyond their capabilities; namely those problemsthat seem to require the agent of human intelligence and ingenuity fortheir solution. It is difficult to characterize such problems further, except,perhaps, to remark rather vaguely that they generally involve complexdecision processes in a potentially infinite and uncontrollable environment.If, however, we should restrict the universe of problems to those thatamount to the discovery of a proof for a theorem in some well-definedformal system, then the distinguishing characteristics of those problems ofspecial interest to us are brought clearly into focus.Proceedings of an International Conference on Information Processing. Paris:UNESCO House, 273-282.
"MANY EFFORTS have been made to discriminate, categorize, and quantitate patterns, and to reduce them into a usable machine language. The results have ordinarily been methods or devices with a high degree of specificity. For example, some devices require a special type font; others can read only one type font; still others require magnetic ink. We have an interest in decision-making circuits with the following qualities: (1) measurable high reliability in decision making, (2) either a high or a low reliability input, and (3) possibly low reliability components. The high specificity of the devices and methods mentioned above was felt to be a drawback for our purposes. All of these approaches prove upon inspection to center upon analysis of the specific characteristics of patterns into parts, followed by a synthesis of the whole from the parts. In these studies, pattern recognition of the whole, that is, Gestalt recognition, was chosen as a more fruitful avenue of approach and as a satisfactory problem for the initial phases of the over-all study."Proceedings of the Eastern Joint Computer Conference, pp. 225-232, New York: Association for Computing Machinery
The studies reported here have been concerned with the programming of a digital computer to behave in a way which, if done by human beings oranimals, would be described as involving the process of learning. Whilethis is not the place to dwell on the importance of machine-learning procedures,or to discourse on the philosophical aspects,1 there is obviously avery large amount of work, now done by people, which is quite trivial inits demands on the intellect but does, nevertheless, involve some learning.Also in Computers and Thought. Feigenbaum, Edward A. and Julian Feldman (Editors) 1963.See also:IEEE XploreSome Studies in Machine Learning Using the Game of Checkers, II - Recent ProgressIBM Journal of Research and Development, 3:211-229