But when we’re talking about what a WordPress site actually is, we’re talking about a series of core files, theme files, and plugin files. This is also known as the anatomy of WordPress.
Core Files
At the core, WordPress is a series of PHP files developed by volunteers around the world. So when your hear someone talking about “WordPress Core” you’ll know what they’re talking about.
The core files provide the key functionality of WordPress. The core functions in these files are used by themes and plugins to customize WordPress.
Theme Files
Theme files control the look and feel of your site. They use special template files like header, footer, and sidebar to generate pages of your site. So if you request a post, you’ll get the single blog post template. If you request a page, you’ll get the page template.
Plugin Files
Plugin files work similarly to theme files, but they let you introduce special functions into any site regardless of theme. Like special apps that perform specific functions, anyone can write a plugin and make it available to the world as long as they follow the WordPress coding standards.
