In WordPress, a hook is a mechanism that allows you to modify or extend the functionality of the core WordPress code or plugin/themes without modifying their files directly.
Hooks come in two types:
Actions:
These hooks allow you to execute custom code at specific points in WordPress core or plugin/theme execution. An action hook usually consists of a function or multiple functions that WordPress executes at a specific point in the code. You can attach your own custom functions to these hooks using the `add_action()` function.
Filters:
These hooks allow you to modify the output or behavior of WordPress core or plugin/theme functions. A filter hook usually consists of a function that takes a value, modifies it, and then returns the modified value. You can attach your own custom functions to these hooks using the `add_filter()` function.
Hooks provide a powerful way to modify the behavior of WordPress core, plugins, or themes without having to modify their files directly. By using hooks, you can make your modification in a way that is more maintainable and upgrade-safe, as your changes will not be overwritten when you update WordPress or the plugin/theme.