What is a Turing machine?

[gopu]

A Turing machine is a theoretical computing machine invented by Alan Turing (1937) to serve as an idealized model for mathematical calculation. A Turing machine consists of a line of cells known as a "tape" that can be moved back and forth, an active element known as the "head" that possesses a property known as "state" and that can change the property known as "color" of the active cell underneath it, and a set of instructions for how the head should modify the active cell and move the tape. At each step, the machine may modify the color of the active cell, change the state of the head, and then move the tape one unit to the left or right.

[lachalton]

A Turing machine is a theoretical device that manipulates the symbols on a piece of tape on a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of a computer algorithm, and is particularly useful for explaining the functions of a processor in a computer.

[abelart]

Turing machine is basically used in algorithm design. Turing machine can run down into a loop, or to a particular state or set conditions, it is required to suspend. Decide on a Turing machine will never stop a given input, and set the rules, is called the halting problem.