A nickname is a word used to substitute for a person's birth name. The term comes from the Middle English word ekename, which means “also-name."
Nicknames are not legal names. They are often given by friends or family members.
There are many types of nicknames. Below are a few examples.

Some nicknames are shortened or different versions of a birth name. For example:
Some nicknames are affectionate or given to honor a person. For example:
Affectionate nicknames are common in sports. For example:
Some nicknames are descriptions. For example:
Using descriptive nicknames is more accepted in some cultures than others. In Thailand, people are often given nicknames based on how they look. For example, someone can be called ผู้ชายสูง (phuchay sung), which means being tall. In some Spanish-speaking countries, calling a child or partner Gordo/a or Gordito/a is an accepted way to express affection.

Nicknames can be unkind, mocking, and/or bullying. For example:
Places can have nicknames too. For example:
Sometimes people or groups get nicknames based on where they live. For example, people from the northern United States (or, overseas, people from anywhere in the United States) are sometimes called Yankees. Nicknames can also be given to tribes. For example, the Dhulbahante tribe are often called reer Darawiish because the former anti-colonial Dervish state was a Dhulbahante state.
Epithets, also called bynames, are descriptive words added with a name.