With both the Weight Loss and Body Definition Plans you will be in calorie deficit. The difference between the two Plans is in the macronutrient distribution.
The Definition Plan is especially suitable for physically active people who want to give their body that final touch, so that you can see the muscles clearly and your body looks generally more cut and defined.
The Nutrition Plans for Weight Loss, on the other hand, are suitable for people who primarily want to lose as much weight as possible. Here’s a summary of which Plan is best for fat reduction.