Automata are said to be theoretical devices which help in understanding the reasoning behind computations and are considered to be ideal rather than realistic. This is because the actual computers cannot have infinite memory as assumed in some automata. The Turing machine is a simple yet powerful mathematical model which is used for accepting and translating languages. It can also be used for evaluating functions. In this paper, the basic terminology related with Turing machine, which accounts for its high computing power, its uses in various areas, its variants, its relation with Artificial Intelligence has been discussed.