Common-collector configuration:

 The common-collector that is abbreviated CC transistor configuration is displayed in figure.  In this type of configuration, the collector is common to both of the input and output of the circuit.  This is fundamentally similar as the common-emitter configuration; apart from that the load is in the emitter in place of the collector.  Just as in the common-emitter circuit, the current flowing via the load while the transistor is reverse-biased is zero, with the collector current being extremely small and equal to the base current.  As the base current is raised, the transistor gradually gets out of cut-off, goes into the active region, and eventually becomes saturated.  One time saturated, the voltage across the load becomes maximum, when the voltage V_ce across the collector and emitter of the transistor goes down to a extremely low value, that is as low as a few tens of milli volts for germanium and 0.2 V for silicon transistors.

Figure:  Common-Collector Transistor Configuration