Question

what is emitter bias configuration

Answer 1

Emitter is the portion of transistor which supplies large charge carriers with respect to base and collector. It is always forward biased so that it can supply large%2iers.
Function of collector is to remove charge carriers from the junction with the base.
The forward biased emitter junction allow low resistance in emitter circuit and hence flowing large amount of current.
The reverse biased collector junction allow high resistance in collector circuit.

Answer 2

Emitter biased circuit generates its own DC bias voltage for the emitter which has a considerable effect on the base current.