“Old” call of duty is based from WWII, which were made in the early 2000s inspired by Medal of Honor while “New” call of duty is the fictionalized takes within the FPS genre (basically the ones you recognize today). Modern Warfare (the 2007 one) is the title that departed from the WWII genre while World at War tackled at both theaters of WWII (the Pacific and European).
I have amazing memories of playing the original during LANs with friends.
The sequel has a special place due to the timing of it and me getting my first apartment. Love using the kar in multiplayer. Oh you guys don’t want to go out? Guess I just play COD all night…darn.
I liked the first MW but fell off the series after that.