We explore the foundations of web and get to grips with the fundamentals of the HTML language. As you will see, its structure and format is relatively straightforward, and you will be able to understand the basics very quickly. We will be focusing on a small number of 'tags' to get started, and also on the ways in which different html files can be linked together to form a site.

To introduce 'style' into a page we need another language - Cascading Style Sheets. This is a different language from HTML and is usually stored in a separate file - the stylesheet.

At the heart of the layout engine in web browsers is a concept called the 'box model'. This defines a general layout structure for all HTML elements, providing a language for specifying important dimensions and relationships to other elements.

Central to a well design site is a clear and understandably navigation structure. This must easily allow the user to explore the site, provide sufficient context such that the user knows where they are at any stage, and do this in a visually pleasing and efficient manner.

Modern web layouts are not considerably more complex and sophisticated than in the past - particularly as mobile is now considered the 'first' destination for any site. To tackle the complex issues CSS Frameworks have arisen as a convenient way to support multiple browsers and different screen sizes & resolutions.

To build a web application we need a web framework. This will define the superstructure of our application and provide essential features to enable us to compose a complicated and efficient web application

Play applications are orchestrated through the routes file. This matches the urls the application can 'serve' to the controllers, which will build the views specific to each request.

A key differentiator between a Static Web Site and a Web Application is forms. This is where the user is invited to entered information - and this data may be retained and stored somewhere.

Keeping track of the currently logged in user is a challenge - as HTTP is, by definition 'stateless'. In Play we have a simple and convenient session mechanism, which can conveniently remember information about the currently logged in user.

Implementing a way of following friends requires a new Model class. This will model a "Friendship" relationship, one of which will be created whenever a user 'follows' another user.