The following is a brief introduction to the Billboard and CMJ Charts, focused primarily how they determine chart positions and differences between the two systems.

Billboard chart, first published in 1958, relies primarily on the Neilsen SoundScan system, which records singles, albums, and DVD sales. When a product (say, a CD) is purchased at a retailer in assocation with SoundScan, the sale is recorded. The second system Billiard uses to collect numbers for the charts is referred to as the BDS, or Broadcast Data Systems. BDS is used to track radio airplay and when a song is played on a radio station associated with BDS, it is recorded into the database as well. The numbers of both the record sales in the Neilson SoundScan-affiliated store and Broadcast Data Systems-affiliated radio station are added up every week to determine the ranking of the album. Billboard charts have since become divided into different genres (Latin, Pop, Rap/R&B, Independent, etc.)

College Music Journal (CMJ), on the other hand, relies on an entirely different system of collecting album popularity. College radio stations, independent record stores, and record companies submit weekly playlists and airplay statistics, and CMJ complies the information from independent college radio station playlists. CMJ then publishes the top 30 in their weekly publication.