Regardless of the type of information entered into the machine or the task being completed, the microprocessor uses its special circuit groups to carry out the three-step process:

1. Fetch: gets an instruction from memory
2. Decode: decides what the instruction means
3. Execute: performs the instruction

The circuitry of a computer is built to follow these steps rapidly and accurately. A desktop computer does these three steps hundreds of millions of times in a second as it completes any given task.

Activities

1. Lets say that in order to know what your next action is to be, you had to fetch an instruction from a box of instructions located in a central location, read the instruction and determine the action required, and final perform the action prescribed by the instruction. How is the action just described similar to or different from the fetch-decode-execute process of a microprocessor?
2. Suppose that there are a million instruction cards. Suppose it takes you about 30 seconds to read an instruction and carry it out. Approximately how long would it take you to process one million instructions?