What is the origin of the idiom "fair and square" and when to use it?

The origin of the idiom "fair and square" can be traced back to the early 17th century in England. The term "fair" refers to something that is just, equitable, or honest, while "square" implies something that is straight, direct, or in accordance with the rules. Over time, this phrase has become a widely recognized and used expression to emphasize the importance of integrity and fairness in various aspects of life.