Computer systems are made of many components and each has a function. You can also call these components as functional units. Memory, CPU, Disks, Input-output devices are some examples of these functional units.
Computer organization is all about how these functional units are organized and how they interact with each other in an overall working of a computer system.
Each topic below contains articles or lessons. You can start reading from top(easy) to bottom(difficult). You must be familiar with digital design concepts before learning from this tutorial.