In WordPress, images are stored in the Media Library. When uploading a new image, WordPress will automatically create a couple of new sizes (thumbnail medium, large, etc) and will store them, in addition to the originals, either in a single folder or organised by year/month, depending on your settings under Settings>Media.
Over the years, those folders will become overcrowded and it will be quite difficult to find specific images you have uploaded some time ago. This might also be challenging especially when redesigning an old website built by someone else.
Export Media Library plugin is very helpful in such situations as it allows exporting only the original image files in a compressed ZIP file and downloads them to your computer for further inspection or even backup. That way, you can obtain a clean backup of all your media files that have been uploaded over the years at your website without getting all other formats that have been created by WP.
The plugin offers the option to download them in a compressed archive or uncompressed.
In addition, you can have all of them in a single folder or by keeping the year/month structure found on the server.
This plugin is not only very efficient and simple to use but also extremely fast performing.