What is the set of operations of a Turing machine? From https://en.wikipedia.org/wiki/Abstract_machine


  A typical abstract machine consists of a definition in terms of
  input, output, and the set of allowable operations used to turn
  the former into the latter. 
  
  The best-known example is the Turing
  machine.



In a Turing machine, what is its set of operations?
Is $\delta$ in the following definition of a Turing machine an
operation? (If yes, then there is only one operation in a Turing machine?) Thanks.

From https://en.wikipedia.org/wiki/Turing_machine


  a (one-tape) Turing machine can be formally defined as a 7-tuple $M=  \langle Q, \Gamma, b, \Sigma, \delta, q_0, F \rangle$ where
  
  $Q$ is a finite, non-empty set of states
  
  $\Gamma$ is a finite, non-empty set of tape alphabet symbols
  
  $b \in \Gamma$ is the blank symbol (the only symbol allowed to occur
  on the tape infinitely often at any step during the computation)
  
  $\Sigma\subseteq\Gamma\setminus\{b\}$ is the set of input symbols
  
  $q_0 \in Q$ is the initial state
  
  $F \subseteq Q$ is the set of final or accepting states.
  
  $\delta: (Q \setminus F) \times \Gamma \rightarrow Q \times \Gamma
     \times \{L,R\}$ is a partial function called the transition function,
  where L is left shift, R is right shift.
The set of operations is what makes the machine work, i.e. read input
somewhere, write output somewhere, and change its internal state
(which includes anything it may change in its memory which can be a
tape or some other device).

In the case of a TM, that is done by the transition function $\delta$.

Now, as you wish, you may see the transition function (actually a
relation, when non-deterministic)) as the unique operation applied
repeatedly. Alternatively you may consider that each instance of the
(arguments, effect) pairs defined by the function, usually defined on
a finite number of possible arguments pairs (state, tape content),
each associated with a finite number of effect triples (state,tape
output,move), are as many separate instructions, the transition
relation being then the instruction set.

It is not a fundamental issue to decide whether you see it globally or
case by case.