The iTunes Store is a software-based online digital media store operated by Apple Inc. Opening as the iTunes Music Store on April 28, 2003, with over 200,000 items to purchase, it is, since April 2008, the number-one music vendor in the United States. On February 24, 2010, the store served its 10 billionth song download and became the number-one music vendor in the world; this milestone was reached in just under seven years of being online. As of October 4, 2011, the store served its 16 billionth song.

While most downloaded files previously included restrictions on their use, enforced by FairPlay, Apple's implementation of digital rights management, iTunes initiated a shift into selling DRM-free music in most countries, marketed as iTunes Plus. On January 6, 2009, Apple announced that DRM had been removed from 80% of the entire music catalog in the U.S. Full iTunes Plus availability was achieved on April 7, 2009 in the U.S., coinciding with the introduction of a three-tiered pricing model; however, television shows, many books, and movies are still FairPlay-protected.