For the uninitiated, the Konami Code is a sequence of button presses that once inputed corrected, will grant players special bonuses that will help said player easily beat the game. This was inadvertently created by Hashimoto when he added this sequence to play test the NES version of Gradius. Code was left out when the game was released, fans discovered it and it became popular that it was reused by Konami developers. The code gained more popularity thanks to the game Contra.
From all of us here, thank you.
[Additional info: Wikipedia]