KPhotoAlbum uses all the images of a directory and all subdirectories below it, first time you start KPhotoAlbum, you will be asked for the location of this directory. KPhotoAlbum will not modify any images, so you do not have to be afraid of KPhotoAlbum altering your images ^[1], actually if you do not trust KPhotoAlbum, feel free to make all your images write protected.

KPhotoAlbum will save all its information in the file index.xml in your topmost image directory. This file is a simple XML file, so you can easily back it up using whatever tools you prefer, including normal backup utilities, copying the file to a floppy disk, or keeping revisions using VCS. There is also a backup script (kpa-backup.sh) provided in KPhotoAlbum's sources that backs up not only the index.xml but also the configuration files inside user's home directory.

KPhotoAlbum will remember where you told it your images were located, and reuse that in future use of KPhotoAlbum. Should you ever want to load another database into KPhotoAlbum (i.e. another directory tree of images), then you may start it with the -c option. For example: kphotoalbum -c ~/CompanyImages/index.xml.