Spirit

Spirits also referred to as ghosts, are the essences or souls of the deceased. When a person dies, their souls are collected by the Angel of Death and taken to the afterlife. However, not all become spirits as some choose to be reincarnated, thus starting a new life after death.

Some spirits remain on earth when they are unable to move on. Usually, this occurs when a person has unfinished business in life, such as being unable to accept their death or when their death was so quick that they still believe themselves to be alive. Spirits may also remain on earth until justice had been done or when they seek revenge themselves. Evil spirits may remain on earth to avoid purgatory.

Appearance
They may be transparent and hazy, while other ghosts like Rick and Nathan Lang were transparent but crystal clear, not hazy. Mark Chao, the first ghost encountered in Charmed, was invisible to everyone except magical beings. When Phoebe Halliwell and Paige Matthews became ghosts, Chris Halliwell once stated they could haunt anybody they wanted.

Book of Shadows
The follow is all information about ghosts and spirits in the Book of Shadows.
 * Banishing a Ghost
 * How to Perform a Seance
 * To Call for a Spirit
 * To Lure an Evil Spirit
 * To Send An Evil Ghost to Judgment
 * To Summon the Dead
 * To Vanquish a Ghost and Return Him to His Rest

Powers and Abilities

 * Wisping: The ability to teleport through wisping lights. When spirits are summoned, they may also teleport through the use of white orbs.
 * Intangibility: The ability to be intangible and move through solid objects. Spirits are naturally intangible, but can become able to become tangible and touch objects when angered.
 * Invisibility: The ability to be unseen by the naked eye. Spirits are naturally invisible to mortals, though magical beings can see them.
 * Hovering: The ability to float in the air a few inches above the ground. Some spirits are seen floating, while others are grounded and can walk.
 * Possession: The ability to enter the body of another being and possess it.
 * Electrokinesis: The ability to manipulate electricity and throw bolts of lightning. Elias Lundy was the only spirit to be shown using this power.
 * Plasma Balls: The ability to throw balls of ectoplasmic energy, capable of vanquishing beings. Olivia Callaway was the only spirit to be shown using this power.
 * Corporealization: The ability to assume a corporeal form. Some spirits are powerful enough to become corporeal. Summoned spirits can also become corporeal when stepping out of the circle they are summoned in.
 * Spirit Writing: The ability to write messages from the afterlife through the use of orbs.

Known Spirits

 * Penelope Halliwell
 * Patricia Halliwell
 * Eva
 * Cassandra Wentworth
 * Melinda Warren
 * Prudence Warren-Wentworth
 * Jonathan Davies
 * Marta Davies
 * Wyatt Halliwell