rights issue

Under the rights issue, the Ex Date is today and the Record date is next wednesday.

I am a little unsure of the exact definition of these terms. Does this mean that you need to have secured the shares by the close of trade on the "Ex Date" which gives enough time to be recorded on the company share register by the "Record Date"?

Is the only date that is really important to the public here the "Ex Date".

Can anyone point me in the direction of a good definition of these terms and how they relate in the australian market.

Thanks.