what is difference between action hook and filter hook in wordpress?

Question

I read the action hook is use for call the functions and filter hook is use for filtering the content before save or display on website. Can you tell me the some working phases of project example where we use action and filter hook. So it will better to understand more.

Answer 1

Action: Doing new things. Ex. adding CSS and JS.

Filter: Doing something which is already in WordPress. Adding or removing some things. Assume adding some text after post content. It means doing something with WordPress.

Example code:

add_action('admin_menu','my_func',8,2);
function my_func($one, $two){
    //Something here …
}