This is an article posted on iO9, a site that seems to be about everything. In it, the author discusses things to be aware of while creating the world your characters live in.
Remember while reading, the article is talking about creating the world, not writing the story. These are things to be aware of while writing that might affect the people in the story, be they the main characters or a creature that comes on and says one line.
Basically, world building is for your benefit so the world your characters walk through doesn’t have major plot holes or come across as unrealistic. The author wants you to take into account the far-flung ramifications of each detail of the world in which your characters live.
Most importantly, none of these rules should break rule #1 of writing: Show, Don’t Tell.
May the muse be with you,