In Reactive Extensions, Operators are chainable methods that manipulate, transform, and combine Observables.
Unlocking the Power of Reactive Extensions
On their own, Observables are just another flavor of the Observer Pattern. The real power behind Reactive Extensions lies in Operators.
Operators are methods that are called on Observables. They perform operations on your Observables to change the way that they behave.
They’re designed to take one Observable as input and then output a completely new Observable. This immutability allows you to chain multiple Operators together to achieve more complex functionality.
It also means that the order in which you call certain Operators is important.
There is a long list of Operators available in Reactive Extensions. As a result, they’ve been split into a number of categories based on the operations they perform.
The main categories are creation, transform