Web development is the process of building websites and web applications. It involves using programming languages like HTML, CSS, and JavaScript to design and create websites and apps that can be accessed on the internet. Web developers work on both the front end, which involves designing the visual interface, and the back end, which involves connecting the website to databases and servers. Popular tools for web development include WordPress, Wix, GitHub, Bootstrap, and programming languages like Python, Java, and JavaScript. Frameworks like Angular, React, and Node.js are also commonly used.