What are the exact applications for psk ,fsk and ask?

1)What are the exact applications for psk ,fsk and ask?
2)as noise did not disturb phase,what is meant by phase noise? can phase noise is a part of every signal and if more than one signal does it affects it neighbors ? 
3) In case of QAM, does noise affect the signal?
4) how to find error in a signal using constellation diagram?

PSK :: biometric passports, credit cards such as American Express's ExpressPay The ASK technique is also commonly used to transmit digital data over optical fiber. Most early telephone-line modems used audio frequency-shift keying to send and receive data, up to rates of about 1200 bits per second. As definition of noise suggests it is not part of phase. Instead it is caused by other sources. Constellation diagram is used to represent the phase direction only. Other techniques are used to error detection.