Custom fields are also called post meta. It is a feature through which users can add arbitrary information when writing a post. These metadata can be displayed using template tags in WordPress themes.

Custom fields in WordPress allow users to add additional metadata or information to their posts, pages, or custom post types. This metadata can be in the form of key-value pairs, where the key represents a certain attribute or piece of information, and the value is the content or data associated with that attribute.

For example, if you’re running a website about books, you might use custom fields to add metadata such as the book’s author, publication date, ISBN, genre, etc. These custom fields can then be used to display additional information about the posts in various ways, such as in custom templates or through plugins.

In essence, custom fields provide a way to extend the default content structure of WordPress and add more specific data relevant to your website’s content or purpose. They offer flexibility and customization options for developers and site administrators to tailor WordPress sites to their specific needs.