In context: In the general genre of open-world video games, whether they be first-person shooters, RPG, or something else, the game's geographical map is vitally important. Not only is it helpful to navigate from one location to the next, the size of the map often gives players a feel for the scale within the game that would otherwise be missed just walking around.
Someone—well actually several someones—made a video comparing various games and the size of their maps from smallest to largest. The sheets are rolled out one-by-one on a virtual table with the game's name, and the size of its geographical area in square kilometers. The virtual maps are roughly to scale, so they are easy to compare visually.
It is interesting to note that while it is intuitive to think that as a franchise progresses, its maps would get bigger. On the contrary, most titles have jumped back and forth between iterations where maps size is concerned rather than always taking the "bigger is better" approach.
There are some surprisingly large locales out there. You can probably guess the two games with maps that make the others look like specks in their worlds, but I won't spoil it by saying anything more.