Adding jQuery to a web form using the script block has some disadvantages. If the application is upgraded to use the latest version of jQuery, all the web forms with the
<script> tag require to be changed. Secondly, switching from the uncompressed version in the development environment to the compressed version in the release environment should be handled manually and is hence error-prone. Using the ASP.NET
ScriptManager control helps you overcome this problem. It can also load jQuery directly from CDN instead of using the local copy.