What is PHP
You may consider PHP as part of the HTML document.
PHP files should be saved with the .php file extension (e.g. myfile.php, test.php)
A block of PHP code starts with "<?php" and ends with "?>" and can be placed anywhere in the HTML document.
A block of PHP code should looks like:
<?php
//PHP commands here
?>
A typical example of PHP codes placed in HTML document should look like:
<html>
<head>
<title>PHP Tutorial</title>
</head>
<body>
<h1>Typical PHP Example</h1>
<?php
//PHP commands here
echo "Hello World";
?>
</body>
</html>
The output of the above typical PHP example should look like:
Typical PHP Example
Hello World
Comments
In PHP codes, all comments are preceded by //. Comments will be ignored by computer. Comments simply allow people to understand your codes as well provide easy maintenance purpose for programers.
Remember that every PHP command ends with a semicolon (;).