WordPress child theme gives you the option to customize a theme without losing your modifications after theme updates.
To use child theme for Massive Dynamic, you need Massive Dynamic theme to be installed and activated. Now you should install Massive Dynamic Child-theme. To do that please follow these steps:
1) Login to WordPress dashboard and then go to "Appreance > theme > Add New"
2) Now click the “Upload Theme” button
3) Please browse to the Massive Dynamic package folder and find massive-dynamic-child.zip .
This is the child theme file that you should install. Choose massive-dynamic-child.zip from the package and then click “Install Now”
4) After installing child theme you should active it
5) Now the child theme has been installed and you can add your custom codes in the child theme files.