JavaScript

Javascript is a scripting language that is used for effects and interactivity within the browser. Browser events such as when a page loads or when a user clicks on a link provide Javascript with opportunities to do something. While these events have been used without consideration, the ability of Javascript to deal with these events can be very useful.

AJAX

Ajax is not a language. It is an application or interactive use of Javascript that allows changes to data on a page without having to refresh the page. This is an example of the true usefulness of Javascript.

CSS

Cascading Style Sheet is the styling language of the Web. CSS allows the developer to separate form and content. In this manner, updates and maintenance become easier, having only to deal with the data.

More