WordPress/wp-includes/block-patterns.php

<?php
/**
 * Register the block patterns and block patterns categories
 *
 * @package WordPress
 * @since 5.5.0
 */

add_theme_support( 'core-block-patterns' );

/**
 * Registers the core block patterns and categories.
 *
 * @since 5.5.0
 * @private
 */
function _register_core_block_patterns_and_categories() {
	$should_register_core_patterns = get_theme_support( 'core-block-patterns' );

	if ( $should_register_core_patterns ) {
		$core_block_patterns = array(
			'text-two-columns',
			'two-buttons',
			'two-images',
			'text-two-columns-with-images',
			'text-three-columns-buttons',
			'large-header',
			'large-header-paragraph',
			'three-buttons',
			'quote',
		);

		foreach ( $core_block_patterns as $core_block_pattern ) {
			register_block_pattern(
				'core/' . $core_block_pattern,
				require __DIR__ . '/block-patterns/' . $core_block_pattern . '.php'
			);
		}
	}

	register_block_pattern_category( 'buttons', array( 'label' => _x( 'Buttons', 'Block pattern category' ) ) );
	register_block_pattern_category( 'columns', array( 'label' => _x( 'Columns', 'Block pattern category' ) ) );
	register_block_pattern_category( 'gallery', array( 'label' => _x( 'Gallery', 'Block pattern category' ) ) );
	register_block_pattern_category( 'header', array( 'label' => _x( 'Headers', 'Block pattern category' ) ) );
	register_block_pattern_category( 'text', array( 'label' => _x( 'Text', 'Block pattern category' ) ) );
}

add_action( 'init', '_register_core_block_patterns_and_categories' );