PHP is a language of scripting that the dynamic generation of contents allows in a web servant. The meaning of his initials is HyperText Preprocessor. Between his principal characteristics it is necessary to emphasize his potency, his high yield, his facility of learning and his scarcity of consumption of resources.

The code PHP can be included inside the code html of the page. To delimit the section of code PHP we can do it of several forms:

- using the tags <? php and <?
- using the tags <? and?>
- by means of <script languaje = "php"> </script>

The functioning of the pages in PHP stayed at a servant is the following one:

- the navigator of the client requests the document PHP.

- the request of the servant comes and the servant locates the document, the interpreter of PHP throws and he executes all his code.

- as soon as the code was executed the result is generated in HTML and he returns it to the servant so that it transfers the client.

- the servant transfers the result in HTML and he is showed in the navigator of the client.