What is the difference btw current amplification factor and current gain? How is it inCE and CB?

@ nayana 
The current amplification factor can be defined as the ratio of the output current to the ratio of the input current . when the current will be flowing in any devices  , it will represent the amount of current gain in that case . 
so, THERE IS NOT ANY DIFFRENCE BETWEEN CURRENT GAIN AND AMPLIFICATION FACTOR . THEY BOTH ARE SAME . 
in common EMITTER IT CAN BE DEFINED AS –
Ratio of small change in collector current to the small change in the base current at constant collector-emitter junction voltage.
hope it clears your doubt 
ALL THE BEST ..