Web development involves building and maintaining websites and includes aspects like design, publishing, programming, and database management. It can be classified into frontend and backend development. Frontend development refers to the client-side interface a user interacts with directly, while backend development involves the server-side functionality not directly visible to users, like data storage. Common frontend tools include HTML, CSS, JavaScript, and frameworks like Bootstrap and React. Popular backend languages are PHP, Java, Python, and Node.js, with frameworks like Django and Rails. Full-stack developers work with both frontend and backend technologies.