What is the meaning of the proverb “A dog barks at the bold, but a coward bites at the coward”?

This proverb is trying to illustrate the differences between courage and cowardice. It is saying that a brave person will confront a challenge, while a cowardly person will back down and run away from a challenge. A brave person will not be intimidated and will stand up to a challenge, while a cowardly person will cower and try to avoid a challenge. The proverb is trying to emphasize that courage is a virtue and cowardice is a vice. Courage is to be admired and respected, while cowardice is to be avoided and condemned.