iPod is a line of portable media players created and marketed by Apple Inc.. The product line-up consists of the hard drive-based iPod classic, the touchscreen iPod touch, the compact iPod nano and the ultra-compact iPod shuffle. iPod classic models store media on an internal hard drive, while all other models use flash memory to enable their smaller size (the discontinued mini used a Microdrive miniature hard drive). As with many other digital music players, iPods can serve as external data storage devices. Storage capacity varies by model, ranging from 2 GB for the iPod shuffle to 160 GB for the iPod classic. The iPod line was announced by Apple on October 23, 2001, and released on November 10, 2001.