hostarchitecture

Host architecture refers to the hardware and software platform on which a computer program is executed or built, as distinct from the target architecture for which the program is intended to run. In practice, it encompasses the processor instruction set, word size, endianness, memory model, and the operating system’s application binary interface that the software relies on. These factors influence portability, performance, and compatibility of software across different machines.

The term is used in several contexts. In virtualization and emulation, the host architecture is the architecture of the physical machine running the hypervisor or emulator. The guest or target architecture may be the same or different, depending on whether full virtualization, para-virtualization, or translation is used. In cross-compilation and packaging, the host architecture describes the machine performing the build, while the target architecture is the machine for which the binary is produced; build systems may also distinguish between build, host, and target.

Common host architectures include x86-64 (amd64), ARM64 (aarch64), PowerPC 64-bit, IBM S/390, and MIPS, among others. Endianness, pointer size, and ABI compatibility are practical concerns when software moves between hosts. Incorrect assumptions about the host can lead to runtime failures if binaries or libraries are not matched to the host’s architecture.

See also: target architecture, cross-compilation, virtualization, emulation, ABI.