What happens when the moon is directly behind the Earth?

A lunar eclipse occurs when the Moon passes directly behind the Earth into its umbra (shadow).

Explanation:

In the first picture, you can see a person handwriting a book. This used to be a lengthy process and took many days or even weeks to complete. 

In the second picture, you can see people using something called the printing press. This allowed people to make books very quickly.

As you can see, the second option is more effective due to the speed at which it can print books.