How does Google Docs handle synchronisation of changes by different users?

For example if a doc is shared to several people and two people make simultaneous changes to it and save, what will it do?|||it creates different versions of the file so that both users' changes are saved. we do this at work all the time, we have our weekly reports on gdocs, and sometimes we have to download them, merge them and then they're fine. If you look in the revision history of each document you'll be able to see who made what changes and if there was a different document saved. it's pretty foolproof.