Computer Architecture is concerned with how hardware components are connected to form a computer system. On the other hand, Computer Organization is concerned with the structure and behavior of a computer system as seen by the user. It is the link between hardware components and software. It maps instructions and data from memory to the execution units of ALU, CU, etc., which carry out the operations. Computer architecture involves designing individual computer components such as CPU, memory system, and I/O systems necessary for a complete computer system. It deals with optimization techniques to reduce costs.