Check out example codes for "how to start jquery". It will help you in understanding the concepts better.

Code Example 1

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>

Code Example 2

<head>

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>

</head>

Code Example 3

<head>

<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.4.1.min.js"></script>

</head>

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