Modern Cameras especially in smartphones and some image editing programs often store unwanted metadata in images you take or create, so you may want to remove them before publishing them on the internet.
In my case it is not that important, but I use it to add source, author and license to all my images on my site to help people keep track of the images, so they know where they are from and if they are legal to use and what author to credit if wanted.
The Exiftool is an allround tool when it comes to reading and editing metadata of images files. Do not wonder, it works only by command line, so take your time to learn the commands. But once you understood it, you can easily read and modify any metadata, especially comfortable is the batch option to edit multiple images in a row.