Resize by enlarging or reducing - just enough to best fit the given size while preserving the aspect ratio.
This option forces the ratio to be ignored so the given size is matched exactly.
Resize based on the smallest fitting dimension. The resized image will completely fill (and even overflow) the given size.
Resize to fit within the given size and then add a border around the image to exactly match the given size.
Crop (cut out parts of the image) to exactly match the given size.