These blocks are meant to be similar to Minecraft blocks. You can stack them and create your own Minecraft world in real life. 

The block file can be colored to be stone, gravel, dirt, sand, gold ore, iron ore, obsidian, glow stone, etc

The smooth block file can be colored to be smooth sandstone, different colors of clay, different colors of concrete, etc

Color it inside your slicer or paint them after they are printed. 

Enjoy :)