!!! Overview
[{$pagename}]  was invented in [1936|Year 1936] by [Alan Turing], and is a mathematical model of a general computing machine. [{$pagename}] is a theoretical device that manipulates symbols contained on a strip of tape. [{$pagename}]s are not intended as a practical computing technology, but rather as a general [model] of a computing machine—anything from an advanced supercomputer to a mathematician with a pencil and paper. It is believed that if a problem can be solved by an [algorithm], there exists a [{$pagename}] that solves the problem. Indeed, this is the statement of the Church–Turing thesis. Furthermore, it is known that everything that can be computed on other models of computation known to us today, such as a RAM machine, Conway's Game of Life, cellular automata or any [programming] language can be computed on a [{$pagename}]. Since [{$pagename}]s are easy to analyze mathematically, and are believed to be as powerful as any other model of computation, the [{$pagename}] is the most commonly used model in complexity theory.

[{$pagename}] are used to define [complexity] classes, such as:
* deterministic Turing machines
* probabilistic Turing machines
* non-deterministic Turing machines
* quantum Turing machines
* symmetric Turing machines
* alternating Turing machines
They are all equally powerful in principle, but when you have a [Bounded Context] (such as time or space), some of these may be more powerful than others.

A deterministic Turing machine is the most basic Turing machine, which uses a fixed set of rules to determine its future actions. A probabilistic Turing machine is a deterministic Turing machine with an extra supply of random bits. The ability to make probabilistic decisions often helps algorithms solve problems more efficiently. [Algorithms] that use random bits are called [Randomized algorithm]. 

A nondeterministic Turing machine is a deterministic Turing machine with an added feature of non-determinism, which allows a Turing machine to have multiple possible future actions from a given [state]. A nondeterministic Turing machine uses [nondeterministic algorithms]. One way to view non-determinism is that the Turing machine branches into many possible computational paths at each step, and if it solves the problem in any of these branches, it is said to have solved the problem. Clearly, this model is not meant to be a physically realizable model, it is just a theoretically interesting abstract machine that gives rise to particularly interesting [complexity] classes.

!! More Information
There might be more information for this subject on one of the following:
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* [#1] - [Turing_machine|Wikipedia:Turing_machine|target='_blank'] - based on information obtained 2019-05-03