Web development has many specialties, with some of the most popular being front-end, back-end, full-stack, mobile, and web design. Front-end development involves building the user interface and interactive elements of a website or web application, using technologies such as HTML, CSS, JavaScript, and frameworks like React, Angular, or Vue. Back-end development involves creating the server-side logic and functionality of a website or web application, using technologies such as PHP, Python, Ruby, Node.js, and databases like MySQL, MongoDB, or PostgreSQL. Full-stack development requires working on both the front-end and back-end of a website or web application with a combination of technologies. Mobile development focuses on optimizing websites or web applications for mobile devices with technologies such as responsive design, progressive web apps, or native apps with frameworks like React Native, Flutter, or Ionic. Finally, web design involves creating the visual and aesthetic aspects of a website or web application with tools such as Photoshop, Illustrator, Sketch, or Figma while also applying principles of user experience and user interface design.