In WordPress development, an action is a specific point in the code where you can make something happen — like running a custom function whenever a post is published, or a user logs in.
Actions are part of WordPress’s “hooks” system. Instead of editing WordPress’s core files directly (which you should never do), developers can “hook into” these action points to add their own behavior safely.
A Simple Example
add_action( 'publish_post', 'notify_admin_of_new_post' );This line tells WordPress: whenever a post is published, run the notify_admin_of_new_post function. That function could send an email, log an event, or trigger anything else the developer defines.
Actions vs Filters
Actions and filters are often mentioned together, but they serve different purposes. Actions let you run code at a certain point without changing any data. Filters, on the other hand, let you modify data before WordPress uses it — like changing a post’s title before it’s displayed.