jQuery Introduction
jQuery Detecting Clicks
jQuery Styling , Fading and Animation
jQuery AJAX
jQuery Regular Expressions
jQuery UI Widgets
jQuery UI Interactions
jQuery Changing the Webpage Content

jQuery Introduction

jQuery is a lightweight, "write less, do more", JavaScript library. The purpose of jQuery is to make it much easier to use JavaScript on your website. jQuery takes a lot of common tasks that require many lines of JavaScript code to accomplish, and wraps them into methods that you can call with a single line of code. jQuery also simplifies a lot of the complicated things from JavaScript, like AJAX calls and DOM manipulation.

The jQuery library contains the following features :

HTML/DOM manipulation
CSS manipulation
HTML event methods
Effects and animations
AJAX
Utilities

Embedding jQuery

To use jQuery in our html file we need to embed jQuery in the required file which can be done in 2 ways :

We can include it from a CDN (Content Delivery Network). Google apis host the jquery. We just need to include the given code in the head tag of html file.
```
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
```
We can download jQuery from here and include the given code in the head tag of html file.
```
<script src="jquery.min.js"></script>
```

Code to check if jQuery is embeded correctly

<html>
<head>
  <title>jQuery</title>
  <script src="jquery.min.js"></script>
</head>
<body>
  hello
  <script>
      if(typeof jQuery == 'undefined') {
      alert("jQuery is not installed properly");
      }
      else {
      alert("jQuery in installed properly");
      }
  </script>
</body>
</html>