Unlike its predecessor Napster, which relied on centralized servers to index files, Kazaa utilized the . This decentralized "peer-to-peer" (P2P) system allowed users to connect directly with one another.

In 2007, a Minnesota jury famously fined a user Jammie Thomas $222,000 for sharing just 24 songs on the network.

In the early 2000s, the digital music landscape was a "Wild West" of innovation and litigation. Following the high-profile shutdown of Napster, a new titan emerged to take its place: . For a brief window, Kazaa wasn't just a software program; it was the primary way millions of people discovered and consumed music, fundamentally altering the recording industry's future. The Evolution of P2P: How Kazaa Worked

However, the bigger threat was legal. The Recording Industry Association of America (RIAA) began aggressively targeting individual file-sharers to deter piracy:

The proprietary technology behind Kazaa was developed by Scandinavian entrepreneurs who would later use similar P2P principles to launch Skype and the Internet TV service Joost . A Double-Edged Sword: Malware and Lawsuits