JavaScript is generally a client-side scripting language, meaning that anything that happens occurs on the user's machine, not at the server. Although it can be used server-side it generally is not. JavaScript can be used to add a little interaction on your webpages, and is great for checking users have entered the correct information when submitting HTML forms. The downside is that some users either do not have JavaScript enabled/avaliable in their browser, so it should generally only be used for non-essiential things. This is generally no big deal as CSS can often provide exactly what you appearance-wise, with much less effort. The following sections are avaliable: