 Welcome to this seventh and eighth module in which we covered JavaScript. And this video is just the introduction to the overall module which consists of a number of smaller videos introducing the different topics. The content is basically as follows. We look at the terminology of client service site, execution client service site applications. We look at the document object model which is an essential part of using JavaScript in the front end for client site applications. And then we dive into JavaScript. So we look a little bit at the history, the versions, different principles, of course a lot of basic syntax how to use JavaScript. Then a couple of the advanced concepts, namely the ones mentioned here are hoisting, callbacks and the JavaScript execution which is often referred to as the event loop simply. And finally we also look at Ajax, at Asynchronous, JavaScript and XML. The learning outcomes are that you should be able to define in contrast what client site and service site applications are. You should be able to define and explain key language concepts of the three languages all together now. So this lecture covers of course only the last part. Similarly, you should be able to develop such applications after this lecture, but also predict how these things work. So looking at a web application based on HTML, CSS and JavaScript and tell how it should behave, how it should look like, behave, how Asynchronous JavaScript behaves, which is a bit more complicated. And then use Ajax to actually add Asynchronous behavior to websites. And finally there are three, I would say more analytical learning outcomes which look at analyzing source code, proposing improvement or improve existing web application code. The literature for this module is again lots of references for looking up different things. The first one is actually an old specification of the DOM of the document object model. It's mainly here for reference because they have a quite nice summary of what the DOM actually is. Then the W3 school is linked here with three different links. The general JavaScript tutorial which covers a lot of different things, a little bit on the history of the different versions and what is supported right now. And then a reference on the different event attributes in HTML that you can use to basically trigger JavaScript. The last two links go into the event loop, into the execution of JavaScript. One explains how this thing works and the other one is a simulation tool where you can actually look at how the code works. So this is the introduction. Please follow the following videos for getting the content.