Hi, sorry for the delay in responding. I've been on a hiatus.
Let's see, generally speaking, one is a manual process ("nodal point") and the other ("panorama assist mode") is an automatic process.
For cameras without a "panorama assist mode" the photographer needs to set it up the good ole' manual way. That is, you pick a point ("nodal point") in front of your lens that you manually pivot your camera around in order to capture images that you can later splice together to make one continuous panoramic image. By setting that imaginary nodal point, you keep your perspective the same.
Now, some digicams feature a "panorama assist mode". Depending on the camera model this could include a viewable ghost image presented on your LCD to line up the next shot against. You use this ghost image as a guide and move your camera until the image you're getting ready to shoot is lined up with it. This may mean moving left or right, forward or backward a tad until they meet perfectly. These shots are then "stitched" together. Some variations of this mode also include such things as white balance and exposure settings lock.
So the basic difference is that one is manual and other is automatic.
