iTunes is a PMP application, utilized for playing and organizing your music and videos. This software is also a program that allows the user to handle the music on iPhones and iPods. Furthermore, this software can connect to the iTunes Store using the Internet to let you buy and download music, videos, TV programs, applications, games for iPods, audio books, podcasts and also, ring tones. It is using to download software for iPhones and iPods that are using the iPhone OS X.
iTunes was released by Apple Inc. on January 9, 2001, to the Macworld Expo, an annual conference kept in  San Francisco. The most recent version of iTunes, the iTunes 9, was released at Apple's September 2009 "Rock and Roll" event.
iTunes is accessible and ready for use and download for free for Mac OS X v10.4+, Windows 7, Windows XP and Windows Vista from Apple's official site. It is also sold together with  all Macintosh computers, and also with some HP and some Dell computers. Elder variants are available for Mac OS 9, Mac OS X v10.0 to 10.3, and for Windows 2000.
iTunes keeps the management  of  the tracks by producing a virtual library storage, permitting that users to be able to access and change a song's assigns. These attributes, named also  metadata, are kept in 2 different library registers.
The 1st is a binary file named iTunes Library and it have a copyrighted file format that it is shorted as ITL. It gets datas like artist or genre from the files format's tag capacities , like the ID3 tag, and depots iTunes typically informations like how many times was played or the rating numbers. iTunes in a typical manner  reads library data only from this files.
The 2nd file, iTunes Music Library. xml, is reviewed every time the information in iTunes is modified. It purposes an XML format, letting program coders to easily write software that can access the library datas (as play count, last played date, and rating, that are not standard domains in the ID3v2.3 format). Apple's own iDVD, iMovie, and iPhoto programs access also this second library.
If the 1st file is corrupted, iTunes will try  to remake  it from the XML file. Detailed 3rd party instructions  concerning  this are documented in another place. There have been some fears, sustained by Mark Pilgrim, who told that this feature will produce an "undocumented binary black hole" for the reason that  the recovery from the XML file may not act properly.
It has also been said that this program does not automatically chase to change into actual datas in the library. If the user will move or erase a file, iTunes will display an exclamation mark near the library introduction and the user will need to amend the library record all by himself. Some 3rd party implemented programs resolve this problem.
iTunes it is used also for ripping the CDs, but it can't rip any DVDs. Even so, in 2008, Apple released iTunes Digital Copy, a program that can do this, as  a bonus attribute  on some DVDs that allows a copy-protected. Like with any other digital music management tool, users have to use a digital converter to import analog recordings, like vinyls or audio cassettes to their iTunes library.
A personal iTunes Library can be shared trough a local area network using the closed, copyrighted DAAP, name that comes from the shorten of Digital Audio Access Protocol, released by Apple for this role. DAAP depends on the Bonjour network service using Frame Work, an Apple provided software. The DAAP specifications aren't available for the general users, but  some 3rd part programmers knows them. An example can be the privately held consumer electronics firm specialized in home digital media products, Roku. Also, the software has been changed and is now used to share play lists from  softwares that don't have the Apple's signature. DAAP permit shared lists of songs between the similar subnets to be automatically recognized. When a song is distributed, iTunes can play the song but won't save it on the local storage device, with the objective of preventing unauthorized copies. Tracks with the AAC format can also be accessed, but the user will need to complete an authentication form. A largest number of users that may connect to another single user in twenty four hours is five. The View options are usually available to iTunes users but the Cover Flow option isn't available when playing a shared library through a network.
