Java Servlets are server-side components that enable Java applications to respond to client requests, typically from web browsers. They operate within a servlet container, which manages their lifecycle and facilitates communication between the client and server. Servlets are designed to handle complex business logic and can generate dynamic web content by processing incoming data and producing HTML responses. They utilize the Java Servlet API, which provides a standard interface for creating web applications. This technology is essential for building robust, scalable web applications in the Java EE ecosystem, making it a fundamental aspect of modern web development.