Downloading jQuery
To get started, first download a copy of jQuery and include it in your document. There are two versions of jQuery available for downloading — compressed and uncompressed.
The uncompressed file is best suited for development or debugging; while, the minified and compressed file is recommended for production because it saves the precious bandwidth and improves the performance due to small file size.
Once you’ve downloaded the jQuery file you can see it has .js extension, because the jQuery is just a JavaScript library, therefore you can include the jQuery file in your HTML document with the <script> element just like you include normal JavaScript files.
Example
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Simple HTML Document</title>
<link rel="stylesheet" href="css/style.css">
<script src="js/jquery-3.5.1.min.js"></script>
</head>
<body>
<h1>Hello, World!</h1>
</body>
</html>Always include the jQuery file before your custom scripts; otherwise, the jQuery APIs will not be available when your jQuery code attempts to access it.
Tip: As you can see we’ve skipped the attribute type="text/javascript" inside the <script> tag in the above example. Because this is not required in HTML5. JavaScript is the default scripting language in HTML5 and in all modern browsers.