Understanding dog interactive behavior and how they behave together will give you a better insight into how your dog's mind works and help you to train them more easily based on these behaviors and their natural instincts. Dogs are pack animals and regardless whether they are in the wild with a pack of dogs or they are in your family, which they see as their pack, their natural instinct tells them to establish their position in the hierarchy of the pack.
In a pack there is a well-defined social structure where every member knows his or her role and position. This basically means, from the pack leader down through the followers, every member knows who he takes orders from and who he gives orders to.
When you see two dogs meeting for the first time, they size each other up to see which one is more dominant and subsequently the sub ordinate or submissive one will adopt a submissive posture such as lying down or showing his belly to the dominant dog.
If the two dogs consider themselves equals there is usually a little tussle until one comes out on top and usually this tussle will determine all of their future meetings. If you own more than one dog you must respect this hierarchy between the dogs or regular fighting may occur.
This generally means, once the dogs have established which of the two are dominant, you should feed him first etc and you will find your dogs do not fight anymore because the dominant one does not feel he has to put the other one in its place.
When you understand why dogs behave the way you do, you see the importance of establishing yourself and the rest of your family as your dog's pack leader which makes training and general life much easier.
Source by Eoin McDonnell