This tutorial discusses the concept of CSS responsive design and how to achieve it using CSS media queries. Responsive web design involves creating a website with an adaptable layout that can adjust to different devices. CSS media queries allow you to customize the website's presentation based on the user's screen size. The tutorial demonstrates how to create a responsive web layout using CSS media queries with an example. It starts by creating four boxes with different names and applies styling to them. The tutorial then explains the use of media queries and how they work. It shows how to use a media query to set the display property of one of the boxes and demonstrates the effect on the webpage. Overall, the tutorial provides an overview of CSS responsive design and the use of media queries to achieve it.