Joomla! advice please

[DoubleCheese]

I've jsut started playing around with Joomla! CMS and I have a testing site hosted online at the moment but un-plublished. I was wondering whether its possible to simply copy the test site, once its developed, into the root directory of the site it will be replacing? Or would I have to start from scratch and upload the installation files and everything all over again?

 

[DoubleCheese]

Thanks for the replies. Just following on from this...I have two .co.uk domains and I'd like to create a one main site and one smaller site. Is it possible to have one Joomla installation that takes care of both sites from one MySQL database? Or would I need two Joomla installations (one for each domain) and if so can they both use the one MySQL database or would I need two?

Thanks.