A Full-Stack Developer is a software professional skilled in both front-end and back-end development. This means they can work on the user interface that people interact with, as well as the server-side logic and database management that powers the application. They are proficient in various programming languages and frameworks, allowing them to build complete web applications from start to finish. These developers often use tools and technologies like HTML, CSS, JavaScript for front-end development, and Node.js, Python, or Ruby for back-end tasks. Their versatility makes them valuable in tech teams, as they can handle multiple aspects of a project, ensuring seamless integration between the client and server sides.