The idea of this work is to explain the SASS system and with the use of it and the application framework called Bootstrap develop a web page which will explain what SASS system is and how it should be used.For developing the web page it is required to at least know the basics of HTML and CSS language because SASS and other extensions offer speed and efficiency advantages. If you are not familiar with CSS it will be harder to understand the SASS preprocessor.By following the examples in this work, it will be easier to create your own web page and understand how these technologies work. The goal of this web page is for it to be responsive or in other words, adaptable to all kinds of screens. To accomplish this, I used Bootstrap framework. In the practical part of this work, there are five HTML files(Home, About SASS, Variables, Nesting and Mixings). In these files it is shown and explained how the preprocessor SASS works.