How did patty die in charmed?

Patty Halliwell, the mother of the Charmed Ones, died in the series due to a confrontation with a demon named Barbas. In Season 1, Episode 12 ("The Witch Is Back"), it is revealed that she sacrificed herself to protect her daughters, Prue, Piper, and Phoebe, from the demon when they were young. In doing so, she used her powers to vanquish him but ultimately lost her life in the process.