Is a blender or a food processor better for preparing baby food?

I would say a food processor. It grinds up the food like mush. A blender would leave chunk in it.

A blender will do the job for soft foods like bananas but for harder foods like brocolli or carrots you will need a food processor

It would depend of the volume of food. I would invest in a 1 or 2 cup food processor because you are most likely making small batches of food. One banana would be perfect for this. Or two carrots cooked with a little seasoning and enough water to allow it to puree. 1/2 cup of oatmeal with a little milk and sugar or maple syrup. The possibilities are endless, and it is so much better for the child and cost effective. You can even puree what ever you have cooked for yourself for dinner.