This is the secondary storage for posts where optional data related to posts and pages are stored. This table consists of four columns. Let's identify some of the most important columns in this table:
| post_id | This is where you find the ID of the post for these additional data. This column is used to form the relationship with the wp_posts table. |
| meta_key | All the additional post data is saved as key-value pairs. This column defines the identification for post data. A unique key should be used for this column with alpha numeric characters, underscores, and dashes. By default, WordPress stores edit lock info for posts and pages. As you add data to posts or create menus, you will see more keys stored with underscore prefixes. ... |
