What makes Java a universal language for developing applications on various operating systems?

Java is considered a universal language for development on different operating systems due to the "Write Once, Run Anywhere" (WORA) concept. This is achieved through the use of the JVM (Java Virtual Machine), which acts as an intermediary layer between Java bytecode and the specific OS. The program is compiled into bytecode, which is the same across all platforms, and the JVM on each OS interprets this bytecode, ensuring portability and independence from hardware architecture and operating system.