Rahul Singh presented on Java. Java is a general-purpose, object-oriented programming language that is designed to have as few implementation dependencies as possible so that code can run on any Java virtual machine. Key principles of Java include that it must be simple, robust, architecture-neutral, portable, and have high performance. Java has undergone several versions since its initial release in 1995 and powers many client-server web applications. The Java platform uses bytecode that runs on a virtual machine, allowing programs to run similarly on different hardware and operating systems. Rahul encouraged attendees to learn Java, citing benefits like its ease of use, rich APIs, documentation support, and platform independence.