• Horizontal Line - A horizontal line is parallel to or on the plane of the horizon. Has a slope of Zero.
• Vertical Line - A vertical line is perpendicular to a horizontal line and is upright through the coordinate plane. Slope is Undefined.
• Slope - The slope is a measure of the steepness of a line or function at any given point.
• Delta 
- The delta symbol signifies a change.
• Ordered Pairs - Ordered pairs are coordinates that can be plotted on the coordinate plane and take the form of (x,y).
• Linear equation - An algebraic equation where the terms are either a constant, a single variable, or the product of a constant and a variable.
