Architecture
Endianness
The convention determining byte ordering when storing multi-byte values in memory.
Detailed Explanation
Big-endian systems store the most significant byte at the lowest address (like reading left-to-right). Little-endian systems store the least significant byte at the lowest address. A 32-bit value 0x12345678 at address 0x100 appears as 12,34,56,78 (big) or 78,56,34,12 (little).
Endianness matters when systems communicate or share data. Network protocols typically use big-endian ("network byte order"). x86 processors are little-endian. ARM and RISC-V can be configured for either.