Computer Architecture and Organization?

Computer Architecture & Organization
Architecture is those attributes visible to the programmer
Instruction set, number of bits used for data representation, I/O mechanisms, addressing techniques.
Organization is how features are implemented
Control signals, interfaces, memory technology.
 
An open architecture allows the system to be connected easily to devices and programs made by other manufacturers. Open architectures use off-the-shelf components and conform to approved standards. A system with a closed architecture, on the other hand, is one whose design is proprietary, making it difficult to connect the system to other systems.