What does it do?
- It can react to events, like when someone hovers over a button or clicks on a link.
- It can read , write, and change the content within the HTML.
- It can be used to validate data before it gets to the server, which saves the server from extra processing.
- It can be used to store and retrieve cookies/information from a computer.
- It can be used to detect the type of browser, and, depending on the browser, it can even load a page specially designed for that browser.