What is the difference between Op-Amp circuit and Comparator circuit?

1. What is the difference between Op-Amp circuit and Comparator circuit?
2. Discuss some of the issues with this Op-Amp oscillations and explain the voltage swing and cause of potential failure of this circuit.
3. What makes the comparator circuit oscillate and more ideal for the applications?
4. Describe the operation of the comparator oscillator circuit and explain the difference in inverting and non-inverting waveforms of the comparator
5. What is the significance of using comparator circuit to achieve sinusoidal oscillations?