Differences between near and far pointers in C, C ++

The near pointer is a 16-bit pointer, which depends on a segment address register. The pointer variable is the displacement. The segment address register + pointer is used for addressing, so there is a limit of 64 K.
The far pointer is a 32-bit pointer, which not only has a 16-bit displacement but also has a 16-bit segment address. However, this pointer has a defect and is added only to the displacement part during incremental operations, once the 16-bit displacement exceeds FFFF, the system returns to the beginning of the segment address.
Therefore, the huge pointer is introduced. The difference between the huge pointer and far is that it is represented by a standardized method, so that all addresses have a unique representation method, this avoids the far pointer issue.
A null pointer specifies a pointer state. Without this NULL pointer, it is like a number without 0.