Hi everyone:
It means appoinment is used for temporaray situation while meetings are conducted for very imporatant decision(in official purpose)Am I right? 
Naz
No. An appointment is a formal reservation for a meeting with a superior.
Is a superior necessary to call a meeting an appointment or would an equated person match too?
Hi Michael,
An appointment is to me simply an arranged time and place for a meeting with someone. This can be with a doctor/dentist/hairdresser/whoever you like.
Alan