Exif data is information about an image, stored by a digital camera. To view Exif info for an image, right click on it from the main screen and
select Exif Info. If you have many selected images one window will open for every image.
The top pane shows the actual Exif info (e.g. Photo date, Camera model etc). This information is for viewing only, so you cannot change it.
On the bottom pane you can see any comments that are stored in the image (only JPEG images). If you want you can write some text and then save it.
Keep in mind that this text will be embedded in the image file, meaning that if you sent this image to someone else, he will be able to
read your comments with the appropriate program (e.g. Cheez ;-)