In computer science, particularly in programming, the term "Observable" refers to a concept commonly used in reactive programming. An Observable is a data structure or object representing a sequence of values or events that can occur over time.

Essentially, an Observable enables the asynchronous delivery of data or events, with observers reacting to this data by executing a function whenever a new value or event is emitted.

The concept of Observables is frequently utilized in various programming languages and frameworks, including JavaScript (with libraries like RxJS), Java (with the Reactive Streams API), and many others. Observables are particularly useful for situations where real-time data processing is required or when managing complex asynchronous operations.