PHP Constants

• A Constant is a name for a simple value.
• A Constant value cannot be changed during the execution.
• A Constant name starts with a letter or underscore.
• A Constant does not required $ sign before it is assigned.
• A constant has global scope across the entire script.
• A constant is set by define() function. It takes two parameters, in first parameter we define the constant 
• name, & in the second parameter we define the value of the constant.

<?php
define("my_message", "i-Technophilia in the best website!");
echo my_message;
?>