000 Hello world

A "Hello world" program is a computer program that outputs "Hello world" on a display device. Because it is typically one of the simplest programs possible in most programming languages, it is by tradition often used to illustrate to beginners the most basic syntax of a programming language, or to verify that a language or system is operating correctly.

In a device that does not display text, a simple program to produce a signal, such as turning on an LED, is often substituted for "Hello world" as the introductory program.[wikipedia]