ECU Differences: 37820-P0G-A50 vs 37820-P0G-A51
 

Was out looking for parts at the Pick-a-part place and found the ECM supposedly for my car (95 ACCORD V6 AT): 37820-P0G-A50, but got home and did a better check to find that the 37820-P0G-A51 replaces the A50.

Does anyone know the difference? Is there a primer on the ECU and what it does and how it works? Usually just let the thing control my car, but the car is getting on and since i have this space ECU, I'd like to know if i can actually use it or if there was some sort of problem since it was replaced.

If anyone has insight, please feel free to let me know.

Thanks,
Teah