Mark Lashoff, a seasoned web development instructor, introduces a course on responsive design. The course aims to teach how to make web designs adaptable to various screen sizes, from mobile devices to 5K monitors. It covers the significance of responsive design beyond traditional websites, including its application in devices like smartwatches and streaming TVs. The course is divided into two sections: understanding the science of responsive design and exploring the HTML and CSS code behind it. Students are encouraged to actively participate, using two screens to follow along with the videos and practice the techniques taught.

What is the importance of responsive design for modern web developers or designers?

Why is it recommended to use two screens while taking the course?