How to Get Connection from Solar Panel. Back Side of The Solar Panel Junction Box and The Function of Diodes in it?

oday, i m going to show the back side of solar panel and its junction box. you will get idea that how to get connection from solar panel junction box.So here we go step by stepimage ( below) shows junction box on the back side of the panel.  you can see two diodes ( why diodes??? we will discuss later) and two terminal wire one of  Positive (+) and other one is Negative (-) both wire will go to charge controller ten battery ( for charging purpose). Note that this60 Watts,12 Volts, and5 Amperes panel but . I am using it for120 Ah battery -