In JavaScript, events are actions that occur when the user or the browser manipulates a page. Events are things that happen in the system you are programming, and they provide a mechanism by which an action can be automatically taken when the event occurs. Events are hooked to elements in the Document Object Model (DOM), and they tend to be attached to a specific item that resides in it. Some examples of events include:

• onclick: This is a mouse event that occurs when the user clicks on the element it is bound to.
• onchange: This event detects the change in value of any element listening to this event.
• onload: This event is evoked when an element is loaded completely.
• onblur: This event is evoked when an element loses focus.

Developers can use these events to execute JavaScript coded responses, which cause buttons to close windows, messages to be displayed to users, data to be validated, and virtually any other type of response imaginable. There are different types of events in JavaScript that are used to react to events, and they can be bound either as inline or in an external script.