Do you know a mac equivalent of ctrl, alt, delete on a pc. My mac sometimes freezes and there is a multicoloured spinning ball. The only thing I can do is turn it off - is there something else I can do?
Has it froze on a particular application? If you go to the apple icon in the top left hand corner in OSX, click on it and go down to 'Force Quit'. This brings up a list of applications running. Select the one that isn't responding and force quit it from there.
PS. Just occured to me, if it's froze that means you can't go to the apple icon with the mouse arrow, in which case the key command for 'Force Quit' are: command / alt / esc. Select the application with the keyboard up and down arrows.