FTP has facilities for sending files. Sending folders just means to send files and subfolders recursively for the selected folder. You need to make sure that any subfolders exist on the target machine, before transferring the files.
What do you have so far? Which FTP API are you using?
Sounds like your reinventing FTP. I'd at least read the doc for FTP to get all the protocol/commands you'll need.
A folder is a construct on an OS that allows you to organize files. Sending a folder would mean a sending a request to the reciever to create a folder by that name. See the MKDIR and ChgDir commands. [ July 29, 2008: Message edited by: Norm Radder ]