The iPod is a hard-drive-based music player from Apple Computer that can play MP3s, WAV, AAC and AIFF files. In addition to playing music iPods may be used as an external hard drive. An iPod is distinguished by its small size, simple user interface based on a central scroll wheel, and fast FireWire connection capable of 400 Mbit/s data transfers.
First announced in October 2001, the iPod was originally available with a 5-GB hard drive. A 10-GB version was announced in March 2002. In July 2002, a 20-GB model was announced, and both the 10- and 20-GB models were updated with a touch-sensitive (rather than moving) scroll wheel, as well as other upgrades. Firmware upgrades have added some PDA functions.
The iPod was originally only compatible with Macintosh computers, but as of mid 2002, Apple Computer has also begun selling a Windows version, formatted to FAT32 instead of HFS+. Third-party products also exist to allow the use of Mac-formatted iPods with Windows computers.
On April 28, 2003, Steve Jobs introduced an "ultrathin" iPod series. These were originally sold in 10, 15, and 30 GB versions. In September 2003, the 15 and 30 GB versions were replaced by 20 and 40 GB versions. Unlike former products, there is no distinction between Mac and Windows versions; one product can be connected to either a Mac or a Windows PC. In the latter case, the user needs to buy an extra USB2 cable because the iPod is basically designed to be connected with FireWire, which is a standard port for the Mac but uncommon in Windows PCs.
iTunes is used to manage files on the iPod when connected to a Mac or Windows PC (as of October 2003). Previously, Musicmatch or ephPod was used to manage files on the iPod when connected to a Windows PC.
Newer iPod accessories include smart-card readers to transfer images from Digital camera cards onto the iPods internal hard disk, and voice recording modules.