Is there a difference between Image Alignment and Stereo Rectification for stereo correspondence or matching?
There two ways to look at this problem.

In simple terms, image rectification warps both images onto a common coordinate frame by typically estimating the transformation using the epipolar geometry.
Image alignment finds the transformation from one image to the other. It doesn't guarantee any constrains on the epipolar geometry and only one single image is warped.

Image rectification might benefit from image alignment (of local patches) to obtain the correspondences. Once these are found, the epipolar lines can be forced to be parallel.