Moving files on the server using a FTP client/commands

Hi i have a photos site and i have currently uploaded to a directory nearly 100 megs.

My problem is, my site always archives previous years and i put the photos from photos/ to photos/archives/2004

I was wondering, is it possible to use FTP to move files between folders, or must i delete everything in photos/ and then reupload it all to photos/archives/2004 ?

I my site is written in PHP, so if this is not available with FTP, could I write a script that does it, and if possible, could someone link me/provide me with an example? Thanks very much