This person might be talking about an engagement announcement, like in the paper... a little blurb you write up saying "hey, we're engaged, we're getting married, it'll be great."

As far as I know, the wedding announcement is something you have ready to send just after the wedding saying something like "partner 1 and partner 2 were married on the fifteenth day of whatever month.... etc." These are sent to people who you didn't invite or couldn't make it, but you would like for them to know that it actually happened.