How change file or folder permissions recursively

To change permissions recursively is easy, but if wanting to change only file or folder permissions, it can be do the next way

An example files:

find /path/files -type f -print0 | sudo xargs -0 chmod 0644

An example folders:

find /path/folders -type d -print0 | sudo xargs -0 chmod 0755

WP shows the text wrong, so read change_permissions text.