An immensely vast and expensive software by Adobe that is not easy to grasp. It is sold together with other fine applications, which, next to editing, also facilitate the management of images and help professional designers and photographers. Most editing functions can also be handled with other open source and free software.
A very useful application, also for laymen. IrfanView allows to view and to present image. Moreover, it is equipped with very practical editing functions: automatic renaming and minimizing images in a folder, lighting adjustments, viewing and editing EXIF/IPTC comments...
A software with a vast scope of functions that lies level with Photoshop. Often recommended by professionals who work with Photoshop. Unfortunately, most of them do not use it. Otherwise they would know that it is not easy to learn. But at least there are good manuals for GIMP.
It is advisable to tag pictures. Add a comment to a JPG file or fill in the so-called EXIF and IPTC information of an image: subject, keywords or author and copyright. Some applications can sort a whole collection of images with the help of these keywords. For free: Adobe Bridge and Digikam (which can also do a lot more.)