Marwan Zouinkhi presents on using Bootstrap, an open-source HTML, CSS, and JS framework, to create responsive websites quickly and easily. Bootstrap allows developers and designers to spend less time on common tasks like layout, navigation, and components so they can focus more on their specific project. The presentation introduces key Bootstrap concepts and components like the navbar, responsive images and galleries, page layouts, and more to demonstrate how it can help build modern, mobile-friendly sites without having to rewrite code from scratch each time.