Custom Events are user-defined events that allow developers to create specific interactions within applications. Unlike standard events, which are predefined by the system, Custom Events can be tailored to meet the unique needs of a project. This flexibility enables developers to trigger actions based on specific user behaviors or application states. In web development, Custom Events can be created using the Event interface in JavaScript. They can be dispatched to notify other parts of the application about changes or actions, enhancing interactivity. This feature is particularly useful in frameworks like React or Vue, where managing state and user interactions is crucial.