Songs you listen to often on Spotify sit, encrypted, on your hard drive. The application looks first for these; if it doesn’t find them, it pulls down 15 seconds of the song from the closest server while it looks for copies of the rest of the song on the hard drives of other users near you. This is file sharing. It increases speed and lowers the demand on central servers by spreading it among several connections. Spotify and The Pirate Bay don’t just share a country; they share an operating system.