You don't understand then how can you support how can you make this person happy so a friend must be a good friend and what is good friend means not only knowing you but also understand knowing by recognizing your face your name may be something outside of your life but if inside that person had nothing knowing nothing about that person of course if we have a good frame we also have a bad friend sometimes that person knowing you understanding you but they always that's why they can guiding you to the wrong path so that's a bad friend. I can understand let's say if I understand someone he's made his major the weakness I can see his feelings his fear so I can blackmail him want something and I guide him to the wrong way to the wrong path to the wrong behave Oslo so some people they know us they understand us but they never do anything to harm us that's called good friend somebody they know us they understand us but they're using us for their own benefit they took advantage of us that's a bad friend.
The Buddha said our good friend will prevent you from doing bad things if you say all I want to do this but if your friends say really let's do it even the friend known as the bad thing but they still support you that is not your friend they must prevent you not to do that.
we all have friends in our life and sometimes we need to be clear some of the friend we just come to say hello and that's it we unable to get along much because we will we may influence negatives from them some of the friends we may influence good things from them so the Buddha gave an example a lot of our good friends but today within our limited of time I just brought out some of the defined about a good friends and a good bad friends and remember again good friend how can this person be called good they knowing you they understand you and the guy you to the good point that's a good friend somebody they know you so well the understanding you so well that's why they use you and they bring you to the wrong way.
https://www.youtube.com/watch?v=PWRy_5ROQZQ