Web development involves creating, building, and maintaining websites and web applications that operate on a browser. It includes tasks like web design, web programming, and database management. While web design focuses on the features and functionality of a site, development refers to the actual construction, or programming, of these elements. The core tools in web development are HTML, CSS, and JavaScript, but other programs like content management systems (CMS) such as WordPress, Joomla!, and Drupal help facilitate the development process, reducing the need to write code from scratch.