Understanding the Basic WordPress Site Components
WordPress is the world’s most popular platform for building websites. Clients often know WordPress is a good fit, but don’t understand the relationship of the basic components. Let’s take a high-level view and make sense of the pieces.
The WordPress Core
When you download the files from WordPress.org you’re getting the core code plus a couple of default themes. Frequent updates to these files are released by WordPress to address security, bugs, and other changes. It’s important not to change the core WordPress files so that these updates can be applied.
A WordPress theme can do many things, but the most noticeable is the layout design. A website built on WordPress can look anyway the designer/developer desires. It has a default layout, but that can be changed entirely. The theme is essentially a separate system of code that dictates the look, layout, content display, and many other features.
WordPress Plug-ins are add-ons to the core code. They provide extra functionality on top of the WordPress base and are often styled visually by the WordPress theme. Like the WordPress core, plug-ins are frequently updated by their authors. If a plug-in is edited, those changes will be lost when the plug-in update is applied. A good WordPress developer will style or edit the plug-in externally to prevent the loss of work.
The username and password for your WordPress site provides access to the online WordPress admin panel. This is place where system, theme, and plug-in settings can be changed, and new content added. You cannot access the WordPress core code or the theme’s code from this administrative panel.
WordPress must be hosted (reside) on a web server. The web server runs the WordPress code and provides the database where content and settings are stored.
FTP is the most common standard for accessing the web server. A separate url, username, and password exist for this utility; a special program is needed as there is generally no web interface. This is where the developer must go to update the theme code and other files that live on the web server.
Below is a diagram that I hope will help you grasp how the various parts relate: