Book of Shadows

The Book of Shadows, often just referred to as The Book, is the magical tome of the Warren Line of Witches. It is the most powerful and coveted tome in the whole world and is over 300 years old. The Book has been passed down every generation ever since it was created by Melinda Warren in the 1693.

Besides all the information about the craft, the Book contains many entries on several beings from the magical community, including demons, warlocks, and other demonic beings. It also contains many spells and potion recipes, most of which were written by Penny Halliwell

History
The Charmed Ones' book was started by Melinda Warren, who began the Warren/Halliwell line of witches, with the year "1693" written on it's cover page. Although it was fairly small then, each succeeding generation of Warren witches had added onto it, particularly information on demons, but also on other supernatural things and magical items they came across and felt necessary to be journaled. One of the earliest entries that was around when Melinda was alive included a curse, and possibly the entry which details the coming of the Charmed Ones, through carvings, though this could've been done by a future descendant. After Melinda was burned at the stake, the Book passed to her daughter Prudence, and was passed down throughout the generations.

The Charmed Ones themselves have added information, spells and potions, as well, for future generations.

A few spells in the Book of Shadows are used for personal gain. No explanation has been given to why such spells would be in the Book but it's likely that these spells were put in to teach future witches about the personal gain consequences; or as to they served a magical purpose to deal with evils of the time.

When Piper and Leo moved to Forks, Piper took the book with her because she felt like she would miss it too much. Phoebe and Paige had no problem with Piper taking it especially since Piper's children were the oldest of the Halliwell family.

Stealing the Book of Shadows
The Source gets a shapeshifting demon to shift into Andrea and go into the Halliwell home to steal the Book. The demon was able to break through the shield it uses to keep from evil beings. Then the Source uses the books spell to take the Halliwell family's powers (except the whiteligher sides) to leave them defenseless against demons. Eventually with the help of Jacob and Sam's pack they were able to get the book back.

Powers and Abilities
The Book of Shadows, is also notable because evil cannot touch it, thanks to the shielding & sensing powers it is blessed with. Nor can it be taken out of the Halliwell Manor, except by the sisters. This is particularly important, as many evil beings covet the book, and the Charmed Ones would be much weaker without its knowledge. Although it is protected by good magic, evil has found a way around this and captured the book several times.

The Book is tied very closely to the Charmed Ones' powers. If one of the Charmed Ones turns evil, the other two will turn evil as well, and the evil will flow through the Book.