mircea2nd 0 Newbie Poster

Hi everyone.
I am putting together a site made out of 2 scripts, with users. So i wonder what's the difference betwen merge or syncronize mysql DB ?
The 2 scripts have info about the members , they will act as one site so i need the users info to be the same on both. When the user fills in the info fields on the first site they should appear on the second as well.
There are few Mysql managers for sync that i could use ... don't know how to yet..
Or the suggestion i got from a friend to copy all the fields from the second DB site into the first one. Except for the fields repeating. Is that a good ideea , will they run slower in time ?
I should say that the first site is community like and the second classifieds, so they will tend to have lots of info stored... hopefully.
The advice i got from the seller of the second script was to syncronize the data bases.

That's about it .. Thanks so much in advance for your answers.