There is no big difference between kidney beans and red beans. Both are just two common names for a variety of common bean with the scientific name Phaseolus vulgaris. They are known as kidney beans because they look more like the human kidney.
They are also known as red beans because they are covered with dark-red skin. The only difference between the two is that while some people might know it as kidney beans, other people, especially in other parts of the world might know it as red beans. Red beans or kidney beans can be cooked in different ways.
Red beans or kidney beans are very rich in protein. However, beans must not be eaten in its raw state as it contains a very toxic substance known as phytohaemagglutinin, which can affect your body. However, in the process of boiling the beans, the toxic substance will be destroyed.