Slope is also known as gradient of line which specifies its incline, steepness or grade. Slope is the ratio of change in the y-coordinates of a point to the change in the x-coordinates of a point. Slope is indicated by "m".

Slope of a line in XY plane with two points $(x_{1}, y_{1})$ and $(x_{2}, y_{2})$ is given by the following equation:
             $m = $$\frac{change   in   y}{change   in   x}$$ = $$\frac{\Delta y}{\Delta x}$
   here, delta "$\Delta$" means the change.             
             $m = $$\frac{(y_{2} - y_{1})}{(x_{2} - x_{1})}$
To find the slope of a line, here are the steps to follow:
Step 1: Name the points $(x_{1}, y_{1})$ and $(x_{2}, y_{2})$.
Step 2: Apply the slope formula,
            $m = $$\frac{(y_{2} - y_{1})}{(x_{2} - x_{1})}$
Step 3: Substitute the values and find the slope of a line.

 Some points to remember while finding the slope :
  •  The slope of a horizontal line is zero as the change in y coordinates is 0.
  •  The slope of a vertical line is not defined as the change in x coordinates is 0.