Changing the name of a large group of files individually can be a real pain in the butt. You may find that files transferred from your digital camera to your hard drive are in order, but their names consist of a group of letters and numbers that usually don't identify the pics themselves.
Plus, after you transfer the files from your camera and delete them from it's memory, the next set of pics taken with your camera can have the same name as the files you've just uploaded.
Different pictures, same name! Flexible Renamer by Naru will take a batch of files and give them the name of your choosing.Flexible Renamer is an excellent file utility that takes large groups of files and allows you to change their names in bulk.