The meaning of this idiom without any elaboration means someone who constantly makes threats but rarely carries them out.

Well, we know dogs are known for barking and biting but they do more than that. A dog protects our homes from invaders by either barking to alert us or scare them off or by biting those intruders. Dogs whenever they see moving cars or people, they bark or want to bite.

Well, there are two types of dogs: ones that bark and ones that bite. The dogs that bark too much, almost never bite. They try to frighten people away by their loud bark. So in life, you will find people who are boisterous and who talk too much but are just empty vessels who are not capable of putting their claims into action. They often boast they will do this and that. These type of people are said to have kissed the blarney stone and have a way with words which unfortunately doesn’t match with their actions.

Then there are those who are quiet, who I woul like to call the biters. They believe more in practice than talk. For them, talk is cheap and they believe that actions speak louder than words. When they want to do something, they do it. They don’t go around ranting or blabbering about their plans of actions. To them, silence is golden. They match their words with their actions. Every word they utter is actually meant and henceforth to be taken seriously.

So, in general, dogs bark or bite when they see strangers. There are dogs that bark too much when they see people but hardly ever bite them. On the other hand, there are dogs that do not bark too much but will try to bite people. With people it is also the same. There are those people who boast about what they are going to accomplish in an exaggerated manner and those who keep quiet and do the work.So, this proverb means that people who talk less are doers and those who talk too much are devoid of action.