Demi Lovato is a person.
Demetria Devonne Lovato ( [ ˈdɛmi_loʊ-ˈvɑːtoʊ ] or ; born August 20 , 1992 ) is an American singer , songwriter , and actress . After making her debut as a child actress in Barney & Friends , Lovato rose to prominence in 2008 when she starred in the Disney Channel television film Camp Rock and released her debut single `` This Is Me '' which peaked at number nine on the Billboard Hot 100 . Her debut album , Do n't Forget ( 2008 ) , debuted at number two on the US Billboard 200 . Lovato was a judge and mentor on the American version of The X Factor in 2012 and 2013 . While promoting the project , Lovato released a book titled Staying Strong : 365 Days a Year ( 2013 ) .