How does walking compare with running

I have recently started walking a little bit with my 63 yr old dad. I know that this is good exercise for me also, but I was just wondering how it compares with running as far as exercise. Mainly I am wondering about the amount of calories burned, and if it is a good cardio workout.
Somebody please let me know.
Nick

Walking is great for seniors like your dad. It is also good for you too if that is all you do for exercise. Running is far more strenuous than walking and it causes you to burn more calories. However, it can be bad for people with degerative bone diseases. If you are young and healthy, you should try some running in addition to walking.

Although some studies that walking is beneficial for health, it is not as beneficial as running or doing some other strenuous activities.

Walking is better than not doing anything but walking doesn't have as good impact on your heart or weight as much as running does.