On this window, you have to set various sizes of output files. If the size is On, the picture will be formed with this size. You can change the image size, aspect ratio and file name suffix. If option Step by Step is On, you have possibility to edit and change EXIF information for each size of picture. So, for example, you can delete all EXIF information for small size picture. The option Step by Step operates only with current picture. For the next size of picture all settings will be restored to default.