Guard dogs patrol a designated area which they consider their home ground. This aggression stems from their natural territorial instincts. This is the reason why guard dogs are able to work on their own without the owner or handler ever being present to give an order or command. The distinct difference between a guard dog and a personal protection dog is that a protection dog takes its lead from the owner and acts on command whereas a guard dog will maintain their duties on their own.
A dog is specifically trained to proceed and act without command. This means the dog will make an all out attack and demobilize anyone who enters the restricted premise without the owner being present to command them.
Dogs are deployed to attack those who trespass onto their property. dogs are generally not used to instill a level of fear in a person and often they will not bark when an intruder is present. Due to the aggressive behavior and lack of social skills, dog typically do not make good family pets. Dogs properly trained and conditioned for guard duty can be somewhat unsteady around anyone except the handler or owner.