Computer was more than just a Monitor and Keyboard

1. Program written

1.1. Each program was initially written by a human in a human-readable programming language such as JAVA, C++, and Python. Then being compiled and made smaller to stored in bits of ones and zeros in memory.

2. CPU needs Instructions

2.1. CPU are looking for the address for the program and send a request to the memory subsystem for instructions. Each instructions is duly fetched and executed. CPU asks memory for the monitor program to find out what the button is.

3. Mouse - optical : measurement with lights and sensors.

3.1. Going to I/O subsystem. Input/output subsystem acts like the eyes, ears, mouth and hands. It's provide the way for computer to interact with its environment. Also, acts like a buffer to keep CPU from being overwhelmed.

4. CPU or Central Process Unit

4.1. The brains of the whole computer. Its job is fetching instructions from memory and executing them. CPU is fetching billions of instruction in a seconds. (Multitask)