Deals with attributes of a computer system that directly affect programmers.
Deals with the elements of a computer system and their inter-connections that realize computer architecture (or decide how it works).
A computer can be broken down into sub-systems, which can themselves be broken down. When dealing with these systems or sub-systems, we are interested in its function and structure.
The functions of a computer system can be broken down into 4 basic components:
Data processing
Data storage This can be temporary storage (memory) or permanent storage (hard disk).
Data movement This deals with data moving in and out of the system (I/O).
Control This controls the above 3 functions. This is decided by the user (through the software he is using).
The structure of a computer system can be broken down into 4 main components:
Central processing unit (CPU) This handles the control and the processing in the system.
Main memory Stores data.
Input/Output (I/O) Moves data in and out of the system.
System interconnectivity This is the means by which communication between the above 3 components is possible.