A Servlet is a Java programming component that runs on a web server and handles client requests, typically from web browsers. It processes incoming data, generates dynamic content, and sends responses back to the client. Servlets are part of the Java EE (Enterprise Edition) platform and are used to create web applications. Servlets operate within a servlet container, which manages their lifecycle and provides various services, such as request handling and session management. They can interact with other Java technologies, such as JSP (JavaServer Pages) and JavaBeans, to create robust and scalable web applications.