Used for both posts AND pages. This is where custom fields attached to a post/page would store their data.
$wpdb->postmeta
meta_id
post_id
meta_key
meta_value
wp_posts
All content types are kept in the wp_posts table and are distinguished from one another by a post type. Default post types are post, page, attachment, revision, and navigation menu.
Navigation Menu – nav_menu_item – This is not an entire menu but a single navigational item on a larger menu.
wp_terms
For the taxonomy system, contains categories, tags, and custom taxonomies.
wp_term_relationships
When terms are hierarchical the relationship between one term and another is stored here. This table is being merged into wp_terms in the future.
wp_term_taxonomy
Used to determine which terms are actually the root level of a taxonomy.