What javascript do?

Answer 1

Javascript works in tandem with HTML (structure) and CSS (style) to provide functionality to web pages.

Answer 2

JavaScript is a "client-side" programming language which means it operates on the client, AKA your Web browser. Webpages are "static" by nature meaning that once the server sends the file to the browser, the server has no memory of the file. JavaScript makes Webpages more exciting by adding "Dynamic" features to "static" files. Imagine a drawing of a person on a piece of paper. Once you draw that person and hand it over for a friend to see, you cannot change it. That means it is "static" and you cannot make any changes to it "natively" because you no longer have it in your possession. That is the same scenario with the Web. The server doesn't have the file in it's possession because it is now on the client. Let's say you want to add a hat to the person. Well, you can't because it is a "static" drawling and it cannot be changed by someone that doesn't have possession of it, Well there is a language called JavaScript that can access the picture and make changes to it. If you utilize this language called JavaScript, you can change that picture that you otherwise could not change before. In summary, JavaScript can manipulate Static files from a Web server when it does not possess them.