The iPod was launched in 2001 as a portable music player that stored audio files. It had a simple interface with a click wheel for navigation. Over time, Apple expanded the iPod line and increased storage capacity. They sold over 275 million iPods from 2001 to 2011. Apple carefully developed the iPod brand through iconic silhouettes in ads, exclusive partnerships, and a large distribution network beyond Apple stores. The iPod's success was driven by its ease of use, large storage, and integration with the iTunes store, creating a closed digital ecosystem around the product.