The program interface is divided into three columns. On the left, you'll have a list of the folders or tags associated with the image; in the center, you'll see thumbnails of the photos; and on the right, you'll have all of the information and key words associated with the images.
All of the tags that you add to the images will be saved in a XMP file in JPhotoTagger's database, so you won't have to worry about changing them somehow.
If you have a ton of photos on your computer and you need to organize them, JPhotoTagger could be just what you've been looking for. It's free, and it allows you to keep your photos well-labled.