Google Music is a music streaming service and was launched today.
Google Music Beta will allow around 20,000 songs and it is free (at least while is in the beta-testing phase).
This service will allow you to listen to music from any device you have with an internet access (phone/tablet Android 2.2, PC). You will also be able to create playlists, mood playlists and manage them instantly no matter what device you use with instantly sync.
With this new service Google has not invented the wheel, online streaming cloud players are services that exist for a long time for example Amazon Cloud Player, mSpot and AudioBox.
On a short comparison between Google Music Beta and Amazon Cloud Player, the most relevant part is that both parties offer around CLOUD 5Gb space (Amazon) or 20 000 songs (at 5Mb/mp3 file that is around 4.6-5Gb). Also Google offers this service only to Andorid users, while Amazon can stream also to iPhone and iPad.
You can read more about Google Music and request an invitation HERE.