Hybrid Theory is the debut studio album by American rock band Linkin Park, released on October 24, 2000, through Warner Bros. Records. Recorded at NRG Recordings in North Hollywood, California, and produced by Don Gilmore, the album's lyrical themes deal with problems lead vocalist Chester Bennington experienced during his adolescence, including drug abuse and the constant fighting and divorce of his parents. Hybrid Theory takes its title from the previous name of the band as well as the concept of music theory and combining different styles.
 
Four singles were released from Hybrid Theory: "One Step Closer", "In the End", "Crawling" and "Papercut", all of them being responsible for launching Linkin Park into mainstream popularity. While "In the End" was the most successful of the four, all of the singles in the album remain some of the band's most successful songs to date. Although "Runaway", "Points of Authority", and "My December" from the special edition bonus disc album were not released as singles, they were minor hits on alternative rock radio stations thanks to the success of all of the band's singles and the album.
 
Generally receiving positive reviews from critics upon its release, Hybrid Theory became a strong commercial success. Peaking at number two on the US Billboard 200, it is certified 12x Platinum by the Recording Industry Association of America (RIAA). It also reached the top 10 in 15 other countries and has sold 27 million copies worldwide, making it the best-selling debut album since Guns N' Roses' Appetite for Destruction (1987) and the best-selling rock album of the 21st century. At the 44th Grammy Awards, it won Best Hard Rock Performance for "Crawling".