Resample is used to optimise large images by resizing them smaller and removing unnecessary file information, though enlarging a resampled image later can result in lower quality due to the discarded information.

1. Optimise Crop Resample Brightness Sharpen & Contrast Resample is used when you resize a large picture to a smaller picture and then throw away unnecessary file information to optimise it. Note one you do it the image when made larger will loose quality.