Definition: "Common" refers to a common set of standards or practices that are widely accepted and used across different contexts. It's like having everything you need in one place, so it's not just for people with certain skills. ".php" stands for "PHP", which is an interpreted programming language created by Brendan Eich at Sun Microsystems in 1995. PHP is the most popular programming language among web developers because of its simplicity, readability, and ease-of-use. "Common.php" could refer to a few things: - The PHP version or code base of a website that's used for many common purposes. - A set of functions or classes defined within a PHP file that are commonly used in the context of a particular application or project. - The PHP extension (e.g., `wp-admin`, `WPAdmin`), which provides additional features and functionalities not available without it. So, "Common.php" could be the code base for many common applications, themes, plugins, etc.