Like the title indicates, even after reading the documentation, it's unclear to me what the difference is between unref(), quit() and end().

• Which one should I use and in which use case ?

end() seems to close a connection without waiting for all the sockets to be closed.
unref() seems to wait for all the commands to end.
quit() seems to be similar to unref().

• Since unref() doesn't have a timeout, is it guaranteed to end or should I set a timeout ?
• Is the end event called unconditionally from which one I called ?