Performing image resizing in a batch process can be tricky. How do you tell Photoshop to resize when you might have a batch of images of varying orientations and aspect ratios? Because batch resizing requires special consideration, version 5 of the Photoshop Automator Actions, contains four different resizing actions.
Resize Image, Change Resolution, Scale Image, and Fit Image all resize your image using different controls. With these four actions you can handle any batch resizing chore you might have, and this video, Resizing Images, explains how they work and why you’ll choose one over another.