# Java

> A long-lived programming language behind many bank systems, big business apps and Android.

- Level: Basic
- Topics: Software
- URL: https://tidbit.legios.com.ar/java/
- In Spanish: [Java](https://tidbit.legios.com.ar/es/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.

## An analogy

A universal power adapter. You build your appliance once, with a standard plug, and the adapter (the JVM) takes care of fitting it into whatever socket each country uses.

## Keep in mind

- Compiled into bytecode that runs on the JVM, on any operating system.
- Widely used in banks, large companies and the backend of big systems.
- Original language of Android; Kotlin also runs on the JVM.
- Not related to JavaScript, despite the name.

## Go deeper

- [Learn Java (dev.java, official)](https://dev.java/learn/)
- [Java (programming language) on Wikipedia](https://en.wikipedia.org/wiki/Java_(programming_language))

## Related terms

- [Programming language](https://tidbit.legios.com.ar/programming-language/): A precise, written language people use to give instructions to a computer.
- [Oracle](https://tidbit.legios.com.ar/oracle/): The company behind one of the most used business databases, now also a cloud provider.
- [Operating system](https://tidbit.legios.com.ar/operating-system/): The base software that runs a device and lets every app share its hardware.
- [Linux](https://tidbit.legios.com.ar/linux/): A free, open source operating system that runs most of the internet's servers.
- [JavaScript](https://tidbit.legios.com.ar/javascript/): The programming language that runs inside web pages and makes them interactive.
- [Power supply](https://tidbit.legios.com.ar/power-supply/): The box that turns wall electricity into the steady, low voltage a computer runs on.
- [Frontend and backend](https://tidbit.legios.com.ar/frontend-and-backend/): The part of an app you see and touch, and the part that works behind it.