A Latin square is a grid arrangement used in statistics and experimental design, where each symbol appears exactly once in each row and column. Typically, the symbols are numbers or letters, and the size of the square is defined by the number of symbols used. For example, a 3x3 Latin square might use the symbols 1, 2, and 3. Latin squares help control for variability in experiments by ensuring that each treatment appears in every position across different conditions. This design is particularly useful in fields like agriculture, psychology, and education to minimize bias and improve the reliability of results.