Say you have a form on your site which, when submitted adds the information to a database. The script on the server makes sure that the information entered into the form is in the correct format. If there is something wrong with the information then you are returned to the page to correct the incorrect items.
Take your time and work through the pages in order, making sure you understand each section before moving to the next. Most of the examples are fairly straight forward and it's recommended that play about with them and make changes to help understand them better.
First we'll take a look at the script tag
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