iTunes Match is part of Apple's latest mobile operating system update, and after a brief delay, it's now up and running. It's a cloud-based storage system that can hold all the music from your computer's library, even the ones you didn't actually buy from Apple. Now all of your 90's hits that you had stored on your old laptop can be digitized and stored in the cloud.
One major tip is that while iTunes Match can store your songs and push them out to any of your devices, it doesn't stream the songs like Google Music or Amazon Cloud Player. Instead of streaming the songs, iTunes Match uploads the songs to your device for playback. That might not make much of a dent in your laptop's storage, but for mobile devices it certainly could.
The service costs $25 per year, and there is a limit of 10,000 songs allowed (not including songs purchased on iTunes). If you think some of the songs in your collection might not be on iTunes Match, it's not likely because there are over 20 million songs in the iTunes Store. One of the best functions of the services is that no matter what quality the songs are in your library, iTunes Match will play them back (and make them available to all devices) at 256-Kbps AAC quality. If iTunes doesn't have one of your songs in its playlist, then it will just upload the track so you can still push it out to any of your other devices.
One trick is to upload your songs to iTunes, and if it's a low quality one, you can then delete it from your computer. iTunes will still have the better quality version of the song and you can download that one. You've just swapped out a low quality version for a better quality in no time. Even if you've tinkered with and edited some of those files, iTunes will save that data too.
Tell us if iTunes Match is a handy feature or if you haven't even gotten the new version of iTunes.