JavaA portable language running on the JVM — dominant in enterprise servers, Android, and big data. promised "write once, run anywhere" via the JVMJava Virtual Machine — executes Java bytecode and hosts Kotlin, Scala, Clojure, and other JVM languages. — same bytecodeIntermediate instructions produced by compilers — often executed by a virtual machine rather than the CPU directly. on Windows, Mac, or UnixAn influential multitasking OS from the 1970s — files, pipes, and C shaped Linux, macOS, and BSD.. In the 1990s it was famous for browser applets (animations, calculators in web pages) and quickly became the default for enterprise backends, AndroidGoogle's open mobile operating system — the dominant platform for smartphones worldwide. apps, and large server systems.

JavaA portable language running on the JVM — dominant in enterprise servers, Android, and big data.'s 'write once, run anywhere' promise reshaped enterprise software and mobile (via AndroidGoogle's open mobile operating system — the dominant platform for smartphones worldwide. later).

It made the JVMJava Virtual Machine — executes Java bytecode and hosts Kotlin, Scala, Clojure, and other JVM languages. model mainstream and pushed garbage-collected OOPObject-oriented programming — organizing code around objects that combine data and behavior. into mainstream industry use.