Billboard is an international newsweekly magazine devoted to the music industry, and is one of the oldest trade magazines in the world. It maintains several internationally recognized music charts that track the most popular songs and albums in various categories on a weekly basis. The two most notable charts are the Billboard Hot 100, which ranks the top 100 songs regardless of genre and is based on physical sales, digital sales and radio airplay; and the Billboard 200, the corresponding chart for album sales.