Well, the food processor chops, slices & shreds as well as purees, but the blender can puree also. I own both.
Both machines have their drawbacks.
1. The food processor has a more powerful motor, but it spins slower than the motor in the blender. It has a wider work bowl, allowing larger volumes of food to be processed at a time.
2. The blender allows you to get a much finer puree because the motor spins faster. But if you are prureeing vegetables, specially squash, it will just sit there and won't move unless you add some liquid to it. The blades are smaller than the one in a food processor.
3. In a blender, you must hold the cover on tightly before you process liquids
or you'll get a bath. In a food processor, the cover is on tightly anyway, since
the bowl and lid must be engaged with the safety start switch to work.
I have not used the blender yet, but the food processor is used just about every time I cook, especially things for holoiday meals like Thanksgiving, Christmas, New Year's, Fourth of July. It's a real work saver when you don't want to take the time to chop, dice, shred or slice things by hand.
And the pulse feature helps keep you from overprocessing certain foods.
~Corey123.