FTP-uploads plus batch-adding is the recommended method to upload files for the admin of a Coppermine-driven gallery. Only the admin can perform this for security reasons; non-admins can not perform this operation and need to use one of the other methods to upload files.
Coppermine is a database-driven app. This means that the files that get uploaded physically reside somewhere on the webspace. This could be any place - folder and file names for the files that get uploaded don't necessarilly have to be sorted in any particular way. The sorting and grouping is a matter of logic though: coppermine uses categories, sub-categories and albums to organize the display of files that were uploaded. To be able to do that, coppermine stores the physical location of the files (the paths that lead to your files) inside the database, as well as some other logical information (for example in which album a file resides).
When a file get's uploaded using your FTP app, Coppermine doesn't "know" where it is, so you have to tell the script the location to enable it to remember the location using the database. This is where the batch-add process comes into play. What the batch-add process does basically is: creating resized copies (thumbnails and intermediate images) of the original files you uploaded and then adding records into the database (one record per file you add) to be able to keep track where on the server's hard disk the file actually resides. With this being said it should be quite obvious: Coppermine doesn't move the files around - they remain where you uploaded them to in the first place.
That's why you should make up your mind in advance about the folder and file structure of your FTP uploads. They need to go into the albums folder, and it's advisable to create a clever structure of folders and sub-folders there.
It is recommended that the coppermine admin use ftp to upload multiple pics/files at a time. Use your ftp software to create sub-folders within your_coppermine_directory/albums/, where your ftp uploads can be saved. Though not mandatory, it's always a good idea to have a folder structure within the albums folder that reflects or mirrors your coppermine categories and albums.
Once you have uploaded your photos by ftp, click on the "Batch Add Pictures" button. The batch-add is performed in three steps:
Once files have been added to coppermine's database, make sure that you never rename or delete them via ftp - use coppermine's admin menu options to remove or rename files, instead. Only in this way will these files be removed from both the file system and the database.