# operation

An operation is a command, instruction or statement execution. Incomputers, these can be arithmetic or logical, asynchronous, synchronous or parallel operations. In data networks, those that serve data transfer or routing.

An arithmetic operation refers to dual arithmetic and the associated basic arithmetic operations of addition, subtraction, multiplication and division. The same applies to the logical operation, which is used tocheck the equality and inequality of values. The third operation, which is derived from dual arithmetic, is the complementary operation. This can be seen in the XOR function or if-then function, among others.

Asynchronous operations are those which do not run synchronously with the clock cycle, but in a time span outside the clock range. Accordingly, synchronous operations work clock-controlled.

Global operations refer to a complete document. An example of a global operation is the full text search. A characteristic of parallel operations is the simultaneous processing of two or more operations. This can be done by multiplexing on one processor, or by multiprocessor systems. Indivisible operations are characterized by the fact that they may not be interrupted, or have an interrupt mechanism that holds a defined operation state.