All three models were released in 2005. As a music jukebox application, iTunes stores a comprehensive library of the user's music on their computer and can play, burn, and rip music from a CD. Devices in the iPod family are designed around a central scroll wheel (except for the iPod photo). The most recent version of iTunes has video organization features. The full-sized model stores media on a built-in hard drive, while the smaller iPod nano and iPod shuffle use flash memory. Computer hardware is the physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware. Most computer hardware is not seen by normal users. The iPod is a brand of portable media players.