Good manners are a set of behaviors that mark someone as civilized and help them fit into social situations. Manners are usually taught from a young age and involve treating others with respect, courtesy, and consideration to make others comfortable. Having good manners can help people develop better relationships and avoid being seen as rude or inappropriate. The document provides examples of good manners like saying please and thank you, holding doors, speaking politely, giving up seats, offering congratulations, proper greetings and introductions, good grooming, and writing thank you notes.