You might wonder why a book targeted at professional web developers is going to spend time covering the HTML form tag. Isn't it easy to understand?
There are two reasons.
The Action and the Method
A form is a container for input elements: buttons, checkboxes, text inputs, and more. It's the input elements in a form that enable a user to enter information into a page and submit information to a server. But what server? And how does the information get to the server? The answers to these questions are in the two most important attributes of a form tag: the action and the method attributes.
The action attribute tells a web browser where to send the information, so naturally the action contains a URL. The URL can be relative, or in cases where you want to send information to a ...