Simple Definition:

Bias is a preference or prejudice [opinion not based on reason or experience] towards a particular person, group, or thing. It can influence how we perceive and interpret information, often leading to unfair treatment or judgment.

Example: A teacher giving higher grades to their favorite student, even if they didn’t do as well as others in the class.

Very Simple Definition:

Bias is when we treat someone or something unfairly because we like or dislike them.

Example: A teacher assumes a certain student is guilty of starting a fight because they dislike the student, not because the student actually started the fight.