JavaScript code is executed by web browsers, which interpret and execute JavaScript code directly within the browser. JavaScript can also be executed on the server-side using Node.js, which allows JavaScript code to be executed outside of the browser on a server. JavaScript code can be executed in two main contexts: client-side and server-side.
On the client-side, JavaScript code is executed by web browsers directly within the browser’s JavaScript engine. When a user visits a website that includes JavaScript code, the browser downloads the code and interprets it to produce the interactive features and dynamic content that the user sees. JavaScript can be embedded in HTML documents using the script tag, or included in external JavaScript files that are referenced from HTML documents.
On the server-side, JavaScript code is executed using a platform called Node.js. Node.js is a JavaScript runtime that allows developers to execute JavaScript code outside of the browser, on a server. With Node.js, developers can use JavaScript to build server-side applications and APIs that run on a server and communicate with clients over the internet. This allows developers to use the same language, JavaScript, across the entire application stack, from front-end to back-end.
Node.js uses the V8 JavaScript engine, which is the same engine used by Google Chrome, to execute JavaScript code. This means that the same JavaScript code that runs in a browser can also run on a server using Node.js. Node.js also provides a wide range of built-in modules and third-party packages that developers can use to build powerful server-side applications and APIs.
In summary, JavaScript code can be executed on both the client-side, within web browsers, and the server-side, using Node.js. Understanding the different contexts in which JavaScript can be executed is essential for developers who want to build complex, scalable, and efficient web applications.