WordPress child theme is a WordPress theme that inherits all functionalities of its parent theme. Child themes should always be used when you need to extend your parent theme and your changes will not be lost once the parent theme has been updated.
One more advantage of Creatus child theme is the ability to override the options files by copying the parent (creatus) theme file in to creatus-child theme corresponding folder;
├─creatus/ │ ├─inc/ │ └──thzframework/ │ └─theme/ │ └─options/ │ ├─posts/ │ └──post_media.php │ └─creatus-child/ ├─inc/ └──thzframework/ └─theme/ └─options/ ├─posts/ └──post_media.php
Once you copy the file over you can make desired changes to theme option file and extend your creatus-child theme options.