Sort of (depends on terminology): A form is a set of controls laid out in 2D. But they are ordered and discrete so you can just ignore their positioning in x,y and instead navigate in their order instead (e.g tabbing through controls) making it a 1D input!
By “2D input” in this context I mean input where there isn’t also such a navigation option and you must input one or more coordinates and there is no way to enter the coordinates as numbers. For example the input surface (image) in a drawing program like Microsoft paint.
I think you're equating "random" with keyboard and "sequential" with mouse, but I also think of keyboard as "serial" and keyboard + mouse as "parallel".
By “2D input” in this context I mean input where there isn’t also such a navigation option and you must input one or more coordinates and there is no way to enter the coordinates as numbers. For example the input surface (image) in a drawing program like Microsoft paint.