What is the difference between amd and intel?

An interesting feature of this processor is that it was the first x86 processor with protected mode. Protected mode enabled up to 16 MiB of memory to be addressed by the on-chip linear memory management unit (MMU) with 1 GiB logical address space. The MMU also provided some degree of prevention from (crashed or ill-behaved) applications writing outside their allocated memory zones. However, the 286 could not revert to the basic 8086-compatible "real mode" without resetting the processor. In theory, real mode applications could be directly executed in 16-bit protected mode if certain rules were followed; however, as many DOS programs broke those rules protected mode was not widely used until the appearance of its successor, the 32-bit Intel 80386, which could go back and forth between modes easily. See Protected mode#Real mode application compatibility for more info.