The Pearson correlation coefficient is a statistical measure that evaluates the strength and direction of the linear relationship between two variables. It ranges from -1 to 1, where -1 indicates a perfect negative correlation, 1 indicates a perfect positive correlation, and 0 signifies no correlation. This coefficient is commonly used in various fields, including psychology, economics, and health sciences, to analyze data sets and understand how changes in one variable may relate to changes in another. A higher absolute value of the coefficient suggests a stronger relationship between the variables being studied.