The slope (aka gradient) describes the steepness of a line. Slope can be
positive, negative, or zero and:
Positive slope means the line rises from left to right.
Negative slope means the line goes downwards from left to right.
Zero gradient means the line is horizontal.
The bigger the absolute value of the gradient, the faster the line increases/decreases. In fact, the value of the slope is exactly the amount by which the line increases/decreases when x increases by one unit. Read more