JavaScript Runtime Environment
1. JavaScript Runtime Environment provides the environment where we can run our JavaScript code.
2. Two JavaScript runtime environments are:
- Browser
- Node.js
Browser
1. A browser is a software application that is used to access and view information on the World Wide Web (WWW).
2. It allows users to interact with web pages, view multimedia content, and surf the internet.
3. The Browser acts as a JavaScript runtime environment because it includes a JavaScript engine that interprets and executes JavaScript code.
JavaScript Engine
1. A JavaScript engine is a computer program that executes JavaScript code.
2. It is a core component of web browsers, server-side JavaScript platforms, and other JavaScript-based environments.
Some Popular JavaScript Engines
1. V8 (fastest JS engine): Developed by Google, used in Google Chrome and Node.js.
2. SpiderMonkey: Developed by Mozilla, used in Firefox.
3. JavaScriptCore: Developed by Apple, used in Safari.
4. Chakra: Developed by Microsoft, used in Microsoft Edge and Internet Explorer (legacy).
Node.js
1. The main reason for JavaScript's popularity.
2. Node.js is a software application that executes JavaScript code. It is not a framework or a library.
3. It allows developers to run JavaScript code outside of a web browser, such as on a server or command-line interface.
4. Node.js uses the V8 JavaScript engine, which is also used in Google Chrome.
5. It is built on top of an event-driven, non-blocking I/O model, which allows it to handle large numbers of simultaneous connections without blocking the execution of other code.
6. This makes it well-suited for building scalable, high-performance applications that can handle a large amount of traffic.
7. Because after the introduction of Node.js, we were able to run JavaScript anywhere like in web servers, as command-line tools, desktop applications, and even IoT (Internet of Things) devices.