In this video the instructor shows how to find the slope of a line given two points that like on the line. Slope of a line is the measure of the steepness of the line compared to the angle made by the line with the x-axes. A line with positive slope slants forwards and a line with a negative slope slants backwards and a line parallel to x axes has zero slope. So if you are given two points (x1, y1) and (x2, y2), the slope of the line passing through those two points is equal to m = (y2 - y1)/(x2 - x1). That is the slope of a line passing through two points is the ratio of difference of y coordinates to the difference of x coordinates. This video shows how to find the slope of a line given two points that lie on the line.