The term architecture refers to a design. In the case of computers, architecture can be thought of as the architecture of the machine, as well as the architecture of the machine's ability to link to other computers or peripherals.

The functional machine may have what is termed an open architecture, where the knowledge of the design of hardware and software is sufficiently public to permit the easy installation of devices and programs from many vendors. In contrast, a computer with a closed architecture has a proprietary design, and can accommodate only select connections, often from the same vendor.

Machine architecture can refer to hardware or software, or to a combination of hardware and software. Furthermore, machine architecture can consider different levels of detail. The architecture of a system always defines that system's broad outlines, and may also define precise mechanisms operating within the system.

The central...