如果Windows 32位上的专用字节相对较低，程序如何具有高虚拟字节数？

I'm trying to get a better understanding of how Windows, 32-bit, calculates the virtual bytes for a program. I am under the impression that Virtual Bytes (VB) are the measure of how much of the user address space is being used, while the Private Bytes (PB) are the measure of actual committed and reserved memory on the system.I'm trying to get a better understanding of how