Java

Java is a programming language released by Sun Microsystems in 1995 and now owned by Oracle. Its big promise was "write once, run anywhere": instead of compiling a program for one specific operating system, Java compiles it into an intermediate format called bytecode, which runs on the JVM (Java Virtual Machine). Any computer with a JVM, whether Windows, Linux or Mac, can run the same program.

Java is strict and verbose compared to newer languages: you declare the type of everything and organize code in classes. That strictness is part of why large organizations trust it. Banks, airlines, insurers, governments and online stores run enormous systems written in Java, some of them for decades. It was also the original language for Android apps, and the JVM runs other languages like Kotlin and Scala.

It is not glamorous, but it is everywhere and still evolving: a new version comes out every six months, and some are designated long-term support releases that companies can rely on for years. Learning Java remains a common path into a programming job. Despite the similar name, it is unrelated to JavaScript.