In russian whats the main difference in saying
Привет
Приветик
Приветник

Is there any rights or wrongs with these informal greetings and if yo break them down what is the comparision in english? And is ик & ник okey to say in infornal situations?

Question

In russian whats the main difference in saying 
Привет
Приветик
Приветник

Is there any rights or wrongs with these informal greetings and if yo break them down what is the comparision in english? And is ик & ник okey to say in infornal situations?

Answer

Привет is informal, we say it to friends or people we know well.
Приветик is also informal, but it’s like “hi there”.
Приветник isn’t correct. We don’t say like that. 
Здравствуйте is formal, we say it to unknown people or persons, that are older that we are, to show them our respect.