1. Positive answer: indicates acceptance and agreement with the other party's words, requests, or suggestions, similar to "okay", "okay", or "no problem".
2. Polite response: As a polite and brief answer in communication, it indicates that one has heard the other person's words and will respond or act accordingly.
3. Short form communication: In instant messaging such as the internet or SMS, using "good" instead of longer replies is a fast and convenient way of communication, saving time and energy.