The x86 architecture, developed by Intel, supports several different operating modes. These modes determine the behavior of the processor and the capabilities available for executing code. Here's an overview of the different operating modes in x86:

1 Real Mode:

• Description: This is the simplest operating mode, reflecting the behavior of the original 8086 processor.
• Addressing: Uses 20-bit segmented addressing, which allows access to 1 MB of memory.
• Protection: No hardware-level memory protection; all code runs with full access to hardware.
• Usage: Typically used during system boot-up and by legacy operating systems or software.

2 Protected Mode:

• Description: Introduced with the 80286 processor, this mode provides advanced features such as virtual memory, paging, and safe multitasking.
• Addressing: Uses 24-bit (286) to 32-bit (386 and later) addressing, allowing access to up to 4 GB of memory.
• Protection: Supports hardware-level memory protection, segment isolation, and privilege levels (rings).
• Usage: Used by modern operating systems (like Windows, Linux) to manage processes and memory.

3 Long Mode:

• Description: Available on x86-64 (or AMD64) processors, this mode enables 64-bit computing.
• Addressing: Uses 64-bit addressing, significantly expanding the addressable memory space.
• Protection: Combines the protection features of protected mode with the extended capabilities of 64-bit computing.
• Usage: Used by modern 64-bit operating systems to manage memory and execute 64-bit applications.