All three models were released in 2005. Computer hardware is the physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware. The bundled software used for uploading music, photos and videos to the iPod is called iTunes. Personal computers, the computer hardware familiar to most people, form only a small minority of computers (about 0.2% of all new computers produced in 2003) Market statistics. As of July 2006, the lineup consists of the 5th generation iPod, with a video player; the iPod nano, with a color screen; and the iPod shuffle. The hardware of a computer is infrequently changed, in comparison with software and data, which are "soft" in the sense that they are readily created, modified or erased on the computer. Devices in the iPod family are designed around a central scroll wheel (except for the iPod shuffle) and provide a simple user interface. The full-sized model stores media on a built-in hard drive, while the smaller iPod nano and iPod shuffle use flash memory. It is in embedded systems in automobiles, microwave ovens, electrocardiograph machines, compact disc players, and other devices. The iPod is a brand of portable media players designed and marketed by Apple Computer. Most computer hardware is not seen by normal users. Discontinued versions include two generations of the iPod mini and four generations of the iPod mini and four generations of the iPod mini and four generations.