An Observable is a programming concept used primarily in reactive programming. It represents a collection of values or events that can be observed over time. When an Observable is created, it can emit data, which can be subscribed to by observers. This allows developers to react to changes or new data as it becomes available. In many programming languages, such as JavaScript with libraries like RxJS, Observables provide a way to handle asynchronous data streams. They simplify the process of managing events, such as user interactions or data fetching, by allowing developers to define how to respond to these events in a clear and organized manner.