Q.With a circuit diagram explain the working of CC amplifier.

In a common-collector amplifier the collector is common to input and output; the signal is applied to the base and the output is taken across the emitter resistor, so the output follows the input in phase. …

[!TLDR]

A common-collector amplifier takes its output from the emitter, which follows the base input in phase and magnitude; its voltage gain is nearly 1 but it has high input and low output impedance, so it acts as an impedance-matching buffer (emitter follower).

Circuit: an npn transistor with the collector as the common terminal (connected to $+V_{CC}$, AC ground). The base is biased by a voltage divider and the input signal is coupled to the base; the output is taken across the emitter resistor $R_E$ (there is no collector load resistor). The base-emitter junction is forward biased and the collector-base junction reverse biased. …