1, knocking at the door is gentle and polite: knocking at the door is gentle and pays more attention to politeness and respect. Holding the knocker or doorknob and letting the knocker or doorknob knock on the door can convey respect and courtesy to people in the house. This method is suitable for traditional doors or doors with rings or handles. Knocking on the door can show good social etiquette in formal occasions or when meeting strangers.

2. Direct and effective knocking: Knocking is a way of knocking directly by hand, which is more concise and direct. By knocking at the door, you can convey your quick intentions and goals, especially for emergencies or situations that require immediate response. Knocking on the door is faster and more effective, which can attract the attention of people in the house and get a quick response.