Pure yogurt and fermented milk are both fermented dairy products, and their differences are mainly reflected in the following aspects:

1. Different additives: pure yogurt contains only milk and yogurt bacteria, does not contain any additives; while fermented milk is based on yogurt bacteria, but also added other probiotics.

2. Different flavors: Plain yogurt has a stronger sour taste and milky aroma, and a thicker texture; fermented milk has a softer texture and is easier to absorb.

3. Nutritional composition is different: the calcium in plain yogurt can be better absorbed by the body, and the calories are relatively low; while the probiotics in fermented milk can enhance intestinal health, and it is easier to play the role of nutritional supplementation.

In short, both plain yogurt and fermented milk are extremely popular health drinks for different needs and tastes, and can be chosen according to personal preference.