Introduction
Sigma is the 18th letter of the Greek alphabet. It corresponds to the letter "S" in the English alphabet. The term "sigma" has also been popularized in certain social contexts, especially online. For example, the "sigma male" concept refers to a man who is independent, self-reliant, and doesn't conform to traditional social hierarchies.
In the nut shell we can say it is the term used to describe the personality of self made men.
