# Hello, JavaScript! The programs in JavaScript are called *scripts*. They can be embedded right into HTML using ` ``` JavaScript can execute not only in a browser, but also on a server, or actually on any device that has a special program called [the JavaScript engine](https://en.wikipedia.org/wiki/JavaScript_engine). Browsers have built-in JavaScript engines, so they can run scripts. We can also run scripts using [Node.js](https://nodejs.org), it's commonly used to build server-side applications. Depending on the environment, JavaScript may provide platform-specific functionality. - In a web 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. Technically, even a coffee machine can include its own JavaScript engine, to allow programming of coffee recipes. ![](javascript-engine.svg) **In this tutorial 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. Turn the page to start learning JavaScript!