 Okay, as a second part of this module we look at the DOM, the document object model, and as a short recap, what happens whenever you get a response with an HTML body from the server, the browser loads this HTML. And this basically means that the browser goes through the code and interprets it and displays the result of that to the user, but you can always view the source. But if we go a little bit into details, what actually happens is that the browser parses the file, so looks at every line, and creates the DOM from it, the DOM. And this DOM is a key concept in JavaScript and in other client-side languages. And basically the document object model, that's what it stands for, is an application programming interface for valid HTML documents. So it's an API that you can use, and then we can look at the second definition by what a W3C here is that with the DOM programmers can build documents, navigate their structure, add, modify, delete elements and content. So basically it's an API that allows you to access the HTML file, the HTML source, if you wish, at the runtime while it's displayed to you and make changes to it. And what this is, this object model is basically a tree of objects, so parts of your website, and these objects represent HTML tags. So this is the object tree, this is the DOM, and then you have methods to manipulate it and to access different elements, read their attributes and so on. So this is the way for scripting languages to access the website. And examples for that are to read fields, for example, what kind of email you put into the input text field, change things during runtime, change the styling or insert, remove new tags. And if we look at this a little bit, this is also from the HTML lecture. You remember that the HTML file or every HTML file is essentially a tree. So you have the dock type on top, then you have the HTML. Within the HTML you have the head, within the head you have the title and so on. And the DOM is basically created to reflect this. So that would look roughly like that. You start with what in the document object model is called the document, that's always the root, and then you add the tags. So first you get to the HTML tag, of course, and then under that you have the head and the body. And then within the head you have the title, and the title has a text attribute that says my first website. So basically what is written between the start and the end tag here. The body, similarly in this example has two tags, an H1 and a P tag, and both of them have text. If you have any attributes, for example, let's say my H1 also has an ID, then you would also have a note that says attribute ID is whatever, my heading. So this is how you can imagine the DOM. And then you basically get methods to access those. For example, there is in JavaScript something that's called document.body that gives it a body element. And then you can do different things with that.