On a web page, things are arranged in order, everything on the page has some information and things it can do. Some of these things can also react when something happens – like when you click a button or move your mouse over something. We call these reactions “events”. If the events are written in javascript then these events are called javascript events.
An “event handler” is like a set of instructions that says what should happen when one of these events occurs. Think of it as a recipe for how the web page should respond to different actions.
Here are some common javascript events you might have heard of:
1. When a page loads, we call it an “onLoad” event.
2. Just before you leave a page, there’s an “onUnload” event.
3. When you move your mouse over something, it’s like an “onMouseOver” event.
4. If you move your mouse away from it, that’s “onMouseOut.”
5. When you submit a form, like filling out your name and clicking a “Submit” button, it triggers an “onSubmit” event.
6. And when you click on something, like a button or a link, it’s the “onClick” event.
JavaScript, a programming language, can talk to the web page and tell it what to do when these events happen. For example, you can use JavaScript to make buttons close windows, show messages to users, check if the information they entered is correct, and do many other things.
These events are a part of something called the Document Object Model (DOM). It’s like a map of the web page, showing where everything is. Every part of a web page, like buttons, text, and images, has a list of JavaScript events that can trigger JavaScript code. This allows web developers to make web pages more interactive and useful.