How can physical address be calculated using protected mode?

In protected mode, physical addresses are calculated using a combination of segment selectors and offsets. A segment selector points to a descriptor in the Global Descriptor Table (GDT) or Local Descriptor Table (LDT), which contains the base address of the segment along with its limit and access rights. To compute the physical address, the base address from the descriptor is added to the offset provided by the program, resulting in the final physical address used by the CPU. This segmentation allows for better memory management and protection in multitasking environments.