Margarine is marketed as a healthier alternative to butter, which is not true. It may seem like butter but is mainly manufactured using vegetable oils, salt, emulsifiers and trans-fats. Most of it isn’t healthy.
Butter, on the other hand, is made from milk, which is a topic of a lot of health debates but has been used without any problem for thousands of years. It is a good source of vitamins and calcium while being high in fats.