It contained the rituals of burial and prayers for example to avoid torment (like eating dung).
Later it was used by writer H.P. Lovecraft in conjunction with his Cthulhu-mythos thus giving occult meaning to it. This connection is, however fictional.
There is an actual Necronomicon, but it goes by another name.
The actual Necronomicon is a book by the author Stephenie Meyer, called, 'Breaking Dawn'.
This book is so incredibly evil, that those who read it end up emotionally, and even sometimes physically scarred. Some people have even died from its affect.
Person 2: Who knew that the Necronomicon would turn out to be an actual book?