In this video, we start our discussion of CSS (Cascading Style Sheets). CSS describes the presentation semantics of our document. Before CSS, we used to change every page to apply the styles we are interested in (for example, the font). But of course this will be a nightmare when we need to change the font (especially if we have tens or hundreds of pages). Using CSS simplify our work tremendously. We start in this video by showing the old way of doing things. Then we progress from there to using CSS inside the page (with the style tag in the header). Then we moved to placing styles in their own files (.css file). We add the styles we need in that file, and we reference the file in our page (by dragging the file and dropping it in the head of the page. We will continue the CSS discussion in the upcoming videos.