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# Hello, JavaScript!
JavaScript has a rich history.
It was created in 1995 as a simple language exclusively for web browsers, to “make web pages alive”. Since then it has greatly evolved.
JavaScript was created in 1995 as a simple language exclusively for web browsers, to "make web pages alive". Since then it has greatly evolved, it's quite far from there it started.
Today we can use JavaScript on many platforms:
- In a web-browser, by embedding it into a web page.
- On a general purpose computer or a server, using [Node.js](https://nodejs.org) and other means.
- ...Or actually on any device that has a special piece of software, called "JavaScript engine".
- ...Or actually on any device that has a special piece of software, called "a JavaScript engine".
Technically, even a coffee machine can include its own JavaScript engine to allow programming of coffee recipes.
![](javascript-engine.svg)
There's a formal language description called [ECMAScript Language Specification](https://tc39.es/ecma262/), it describes how a JavaScript engine works. Sometimes we'll give references to it, but, though technically strict, it's hard to read for humans. At least at first.
There's a formal language description called [ECMAScript Language Specification](https://tc39.es/ecma262/), it describes how a JavaScript engine works. Sometimes we'll give references to it, but, though technically correct, it's hard to read for humans.
Programs in JavaScript are called *scripts*.
Programs in JavaScript are called "scripts".
Browsers have built-in JavaScript engines, so they can run scripts. They can be embedded right into HTML using the `<script>` tag and run automatically as the page loads.
**In this tutorial we concentrate on the "core" JavaScript, that works mostly everywhere.**
For example, this HTML-page shows the "Hello, world!" message:
```html run height=0
<!doctype html>
<script>
alert("Hello, world!");
</script>
```
To see it in action, you can click the "run" button in the upper-right corner. Also you can create a new file, e.g. `my.html` with this text and open it locally in a browser.
Depending on the environment, JavaScript may provide platform-specific functionality.
- In a browser, JavaScript can manipulate the web-page, send network requests, show messages and so on.
- In node.js we can use JavaScript to run a web-server, read and write arbitrary files.
- ...And so on.
**In this course we concentrate on the core JavaScript, that's the same everywhere.**
We'll try to keep browser-specific notes at minimum. After you learn the core, you can go in any direction: browsers, frameworks, servers and so on.
Then, after you're familiar with it, you'll be able to move in any direction: browsers, servers and so on.
Turn the page to start learning JavaScript!