Web.dev is a website that is dedicated to helping web developers to improve their skills and knowledge in creating high-quality websites. It is a platform provided by Google that houses various tools, resources, and guides that are aimed at making the web work for everyone. The website provides a wealth of information that covers topics such as web performance, accessibility, security, search engine optimization, and many more. On this platform, developers can also find various sample projects that they can use to test their skills and knowledge, as well as interactive tutorials that are designed to help them improve their skills.