Purpose

Loads the WordPress environment and runs the front-end request lifecycle (query + template).

Flow

• Ensures it only runs once via $wp_did_header guard.
• Requires wp-load.php to bootstrap WordPress.
• Calls wp() to set up the main query.
• Requires template-loader.php to load the appropriate theme template.

Key functions called

• wp()
• require_once ABSPATH . WPINC . '/template-loader.php'

Hooks fired

• None directly in this file. Hooks fire during wp() and template loading.