For instance, you can use JS to create a gif on the fly. Or you can make your page interactive by using a slider to change the appearance of your content. Using JS to do these things is not as hard as it might seem.
A similar feature is the ability to use data validation on your site. In other words, you can filter out invalid characters from your server without having to worry about the actual validation process.
There are also several other features to mention. One is the fact that it can execute scripts directly in a browser, so it’s faster than other technologies. Additionally, JS is cross platform, so it’s compatible with all major browsers. Some of the more popular uses for JS are for games, user interfaces, and web apps.