Let’s take a brief overview of the folders and files that constitute a typical WordPress installation, starting with the Root Directory.

/

The root directory houses essential WordPress files. For regular users, accessing wp-config.php is typically the only necessity, as altering other core WordPress files is strongly discouraged.

Modifying core files poses the risk of being overridden during WordPress upgrades. Interaction with the wp-content directory, containing plugins, themes, and uploaded files, is generally the only requirement.

When tempted to modify a core WordPress file, reconsider.

It’s likely that a hook or filter can achieve the same objective. If a suitable hook or filter doesn’t exist, consider proposing its addition to the core. The WordPress developers are responsive to incorporating new hooks and filters.

Another file in the WordPress root directory that may require updates, depending on your setup, is the .htaccess file.

Although not a WordPress core file, it plays a crucial role in handling directory configuration, permalinks, and redirects, automatically created by WordPress when defining the permalink structure.

/wp-admin

This directory manages the WordPress admin dashboard interface, including the key file admin-ajax.php, handling all Ajax requests.

/wp-includes

Containing core files for various WordPress functionalities, the wp-includes directory invites users to explore its structure and code to gain a deeper understanding of WordPress’s inner workings.

/wp-content

Empowering users and developers, this directory allows customisation of WordPress. It encompasses sub-directories for installed plugins, themes, and media files.

The wp-content directory includes several sub-directories:

/wp-content/plugins

Housing installed WordPress plugins, including the default Hello Dolly and Akismet plugins.

/wp-content/themes

Containing installed WordPress themes, with default themes named after the release year (Twenty Seventeen, Twenty Nineteen, etc.).

/wp-content/uploads

Storing uploaded media files, this directory populates as you add photos or files to your media library.

/wp-content/mu-plugins

The “must-use” plugins directory, created manually inside wp-content, forces the use of specific plugins without manual activation.

Particularly useful in multi-site WordPress installations, these plugins cannot be deactivated by individual network site admins.

Check for the mu-plugins folder on existing sites to uncover potential overlooked plugins affecting site functionality.