A music download is the transfer of music as a digital file from a provider (such as iTunes) to a device capable of playing it; legal sales of music downloads have been monitored and charted in the United Kingdom since 2004. , the UK's most-downloaded song of all time is "Happy" by Pharrell Williams, which topped both the UK Singles Downloads Chart and UK Singles Chart.
The first single to sell one million downloads in the UK was "I Gotta Feeling" by The Black Eyed Peas and "Someone like You" and "Set Fire to the Rain" by Adele are the best-selling downloads by a female artist. The best-selling song not to top the UK Singles Chart is "Moves Like Jagger" by Maroon 5 featuring Christina Aguilera, whilst the best-selling song not to top the Download Chart is "Love the Way You Lie" by Eminem featuring Rihanna, which peaked at number two.