Why Call of Duty?

Call of Duty is known for it's fast action,3D graphics,and some what dynamic themes, it's known for having multiple series from Call of Duty 1 to Call of Duty:Ghost, unlike Battlefield, COD is has two creators that relate the game far from each other, COD is also known for having a few modern day weapons such as the Remington,Five-seven and few others,but mainly focus on non-existing weapons and more futuristic versions of modern weapons for example: M4A1=M8A1,