What is: Hooks
Hooks are the functions used to manage Action or Filters in WordPress. Actions and Filters are functions used to change the default functionality of WordPress.
Hooks can also be defined as an event when you want to customize something, you can use a hook, a function. Actions are the functions when some event occurs in WordPress and Filters are to modify those functions.
WordPress provides many hooks that you can use, you can also create your own hooks to perform certain events. You need to write a function called Callback to trigger the actions and filters.
The Action function is written to perform some event. You never get a callback from the Action function, it just performs the task.
The Filter function performs the task and modifies it and returns the call back to the hook for further modifications.