The Y-Intercept is the point where a line crosses the vertical axis (the Y-axis) on a graph. This point represents the value of Y when the value of X is zero. In a linear equation, it is often denoted as b in the slope-intercept form, which is Y = mX + b, where m is the slope of the line. To find the Y-Intercept, you can set X to zero in the equation and solve for Y. For example, in the equation Y = 2X + 3, the Y-Intercept is 3, meaning the line crosses the Y-axis at the point (0, 3).