Music Industry
A digital download (also known as a digital single or a paid digital download) is an official and legal music single available for purchase through an online store. Popular examples of online music stores that sell digital singles and albums include Apple's iTunes and Napster.
Digital downloads are often encoded with DRM that make it impossible to make additional copies of the music or play purchased songs on a playing device from a competing hardware manufacturer. For example, songs purchased from Apple's iTunes will only play on Apple's iPod. A way to get around DRM is to burn purchased songs to a CD, then transfer them onto the computer again from the CD in the desired unprotected format. Movielink | Downloadable Movies are Here. This results in a slight loss of sound quality due to additional encoding/decoding of the music (called transcoding).
Legal music downloads have existed since 2000.
 United States
Legal music downloads were first compiled by Billboard in 2003, but they didn't gain mainstream acceptance in the United States until around February 2005, when digital sales for singles started to be included in the Billboard Hot 100 and other Billboard charts. In the year before, the Hot 100 chart was very similar to the Hot 100 Airplay chart, because there were only minor CD-single sales affecting the chart. The inclusion of digital singles has immensely helped many songs chart and peak higher, including Jessica Simpson's "These Boots Are Made for Walkin'" which became her second-highest peaking Hot 100 single thanks to digital sales. best-movies-downloadscom.