The database is split into two sections. The Idol Database lists everything to do with American Idol: contestants, performances, results, songs, TV ratings, Dialidol, WhatNotToSing approval ratings, Votefair popularity, and many more. The Song database focuses on songs alone: Billboard ranking, year of release, how often it's played on the radio, etc. However, the two parts link together. The Idol database links every song to the song database, and the song database will tell you if the song has ever been performed on Idol.
Looking for something in particular? Try the search box above. It will look through the Idol database for contestants and through the song database for song titles and artists.