what does that mean bank one and bank two???
Bank 1 is whichever “bank” of cylinders has cylinder 1 on it.
If you have a 4 cylinder engine it only has bank one.
But e.g. for a 6 cylinder, there is one “bank” of cylinders on one side and another “bank” on the other. Bank 1 is whichever side has cylinder 1. Bank 2 is the other side.
I don’t know about bank two, but Bank One has merged with Chase Bank. 
“V” engines have 2 “banks” of cylinders… Bank 1 is USUALLY the front facing or the one on the DRIVERS side.
Cig is correct… Bank one is where ever the cylinder labeled as #1 is…