Rottweilers were domestic working dogs and now used by cops as search and rescue dogs. This breed has abundant strength, courage and serve as exceptional guard dogs and also great with familie, when trained and socialized properly. They have a very strong jaw power and are very intelligent. Rottweilers need a calm. stable pack leader as described by the American Rottweiler Club. 

Rottweilers are very protective of their territory and not friendly with strangers. They need to be taught obedience training and socialization. In many films, they might have portrayed rottweilers in a vicious manner. But they can be brought up in a well behaved manner with training. With that, you will have a wonderful companion.