iTunes is available for both Macintosh and Windows operating systems. With iTunes, you can:

Listen to CDs: iTunes will play your music CDs like a regular CD player.

Import music from your CDs: iTunes can import (or rip) music from your CDs. You can import in AAC (the codec underlying MP4), MP3, AIFF, WAV, or Apple Lossless Encoder formats. The music will then be stored on your hard drive for access anytime.

Convert music to a different format: After you have imported your music files into iTunes, you can convert them to a different format (e.g., MP3 to AAC or WAV to MP3).

Listen to and view podcasts: Through the iTunes Store, you can search for and subscribe to podcasts. Whenever you open iTunes, the latest episodes of these free audio and video programs will download automatically to your iTunes Library.

Buy music and videos online: Through the iTunes Store, you can purchase music, audiobooks, movies, and episodes of television shows. If you want to put your favorite ipod songs to ituens, the guide on how to put songs from ipod to itunes can help you a lot.

Export to a non-Apple MP3 player: You can export your playlists to a non-Apple commercial MP3 player through USB or USB 2.0. To upload files, drag them to the MP3 player icon.

Buy iPhone, iPod touch, and iPad apps online: Through the iTunes App Store, you can purchase applications for your iPhone, iPod touch, or iPad.

Create playlists: Once you have stored your music on your hard drive, you can play it in any order you like by creating a playlist. You can organize your music according to artist, album, or song title as well.

Synchronize with your iPod, iPhone, or iPad: When you plug in your iPod, iPhone, or iPad, iTunes will synchronize automatically at high speeds over FireWire or USB 2.0.

Listen to Internet radio: iTunes features a built-in Internet radio tuner that will find Internet radio stations by genre.

Play movie trailers: You can view movie trailers available on Apple's web site. To do so, search the iTunes Music Store from within iTunes, or visit iTunes Movie Trailers. If you are also a film fan like me, that would be great.

Listen to music shared across the network: You can choose to make your Library available to other iTunes users on your local network, and you can likewise access others' iTunes playlists. The available playlists appear in iTunes automatically.

Visualize your music: iTunes includes a music visualizer that plays a light show along with the music.

And another is iTunes Playlists.Well, how to Make a Custom Playlist Using iTunes. A playlist is a custom list of music tracks that is made up from songs in your music library; you can think of playlists as your own music compilations. You can make as many playlists as you want and give them any name you desire. It is sometimes useful to organize tracks into playlists to suit a particular musical style or mood. This tutorial will show you how to generate a playlist from a selection of songs from the music library folder.

If you haven't got any music in your iTunes library yet then the quickest way is to import your CDs (see the tutorial on CD ripping). The article on the dos and don'ts of CD copying and ripping is also a useful resource to read. If you have got many songs in your iphone, I think move playlist from iphone to itunes is a good choice for you.

If you need to install iTunes first on your Mac or PC, then the best place to get the latest version is to download it from Apple's web site.

And now, iTunes still growing faster than peers at 7 years old. It was not hard to see that iTunes was not only growing quickly even over seven years but faster than some longstanding platforms. At 225 million accounts, it was still growing at a logarithmic scale, Asymco saw. The Xbox 360, Windows Mobile, and Symbian had tapered off either at the same seven-year mark or earlier.

With the development of technology, the itunes is becoming more and more powerful.  I am sure that it will be better and better. Oh, well, iTunes is available free from Apple's Download iTunes page.