Custom post types are content types similar to posts and pages in wordpress. A post type can be anything like products in woocommerce, Products is also custom type and let’s say we can create testinomials as custom post type.
Custom post type generator is free tool from Sigmascripts. It will create custom post type for you. All you have to just fill the values, It will auto generate the code and you just need to copy and paste that code in your function.php