The equation "Y = mX + b" represents a linear function in mathematics. In this equation, Y is the dependent variable, X is the independent variable, m is the slope of the line, and b is the y-intercept. The slope indicates how steep the line is, showing the rate of change of Y with respect to X. The y-intercept, b, is the point where the line crosses the y-axis, meaning it is the value of Y when X is zero. This equation is commonly used in various fields, including economics, science, and engineering, to model relationships between two variables.