Shirk is a major sin in Islam that refers to associating someone or something with Allah. In other words, shirk means comparing something or someone as equal to Allah.

There are two types of shirk:

1. Shirk Akbar

Shirk Akbar refers to the greatest form of shirk, which is not believing that Allah is one and worshiping other idols or gods beside Him. Major shirk is the only sin in Islam that is unforgivable by Allah.

2. Shirk Asghar

Shirk Asghar refers to minor shirk, which involves actions or beliefs that do not entirely remove a person from the circle of Islam. In this sin, people still believe in one God, but they think that other things or people can bring them closer to Allah.