The amount of light seen represents the development or underdevelopment of a region.The world is nearly alight in the three main developed areas: North-America,Western Europe and Japan while the south is mostly in darkness (except for relatively more developed areas such as Australia, South Africa and Brazil).But you should not forget to look at the natural boundaries too, like the Sahara and the rain forests. It's interesting how the population (or is it only the electricity?) of China is so unevenly distibuted. On the other hand how India's pop. appears to be evenly spread, not surprising since India's population is almost as large as China's in a very much smaller space.

It's also interesting to observe how the lights tend to concentrate around the edges of the continents: after all, 25% of the 6 billion population in the world lives along the coastlines. If you can get a close-up of the river Nile, you'll see how it literally glows, and how dark it is around it.

Also the great difference in luminosity between North and South Korea, for instance. Well, these are just some of the things you can take out of this picture. Have fun and see what other conclusions you can draw.