What is the purpose of the capacitor?

1.DC blocking: The role is to prevent DC from passing and let the AC pass.

2.Bypass (decoupling): Provides a low impedance path for some of the parallel components in the AC circuit..Temperature compensation: compensates for the influence of other components on the temperature, and compensates to improve the stability of the circuit.

6.Timing: Capacitors are used in conjunction with Resistorss to determine the time constant of the circuit.

7.Tuning: System tuning of frequency-dependent circuits such as cell phones, radios, and televisions.