Sometimes you experience a strong sense of familiarity about an event that shouldn’t be felt familiar or the eerie feeling that you have seen this exact thing before. Yes, it is **déjà vu**.

Most of you heard the word déjà vu and also experienced it. Because it’s a very common thing as **60–70% of people** (or **2/3 population)** experienced it. It is more common in young people of ages **15 to 25 years old**, and it never occurs before **age 8 or 9**. Its episodes last between **10 and 30 seconds**. …

In the previous part we look at entropy in the retrospect of energy, while this part will focus on the entropy in the paradigm of probability and Information theory.

So, like last time we’ll use an example to understand the entropy in probability theory.

Suppose we have 3 sets of balls, each set contains 4 balls. The First set consists of 4 green balls, the second contains 3 green and 1 yellow and the third or last set consists of 2 green and 2 yellow balls.

The Most popular definition of entropy is

Measure of Disorderliness or Randomness in a system

But this definition is quite general. We can look entropy from another angle. For that we have to understand the concept of entropy in depth through an example.