Since physical memory is the RAM where is logical memory stored on the computer?
I'm not sure what you mean by "logical memory"...

Memory is usually composed of physical memory and virtual memory. Physical memory is usually RAM, hard drives, solid-state drives, etc. It's the actual chips and stuff you plug into your computer (hence "physical").

However, it would be impractical if a larger scale OS is trying to run various applications at once and we only use this memory in a sequential manner, right? That's where virtual memory and virtual mapping comes into play. It's a matter of optimization used by the OS to improve performance.

"It" isn't exactly "stored" anywhere.