imagemagic resize scale

What is the difference between resize and scale?

I have a slow (qnap/arm) server and using convert -resize ... it takes over 2 minutes to resize a normal photo. Using the scale method it "only" takes about 20 seconds. This relly improves the experience for me when resizing lots of images...

Is there any other way to speed up the conversion?

The change in image.imagemagick.inc:

$ diff image.imagemagick.inc image.imagemagick.inc~
76c76

<  *   String with the operation: 'scale', 'crop', 'rotate'.