Quadrants: Any of the 4 areas when we divide up a plane by an x and y axis.     

Vertex: A point where two or more line segments meet. A corner. (Plural of vertex is "vertices")

Coordinate: A set of values that show an exact position on a graph.

Linear Equation: An equation for a straight line. y=mx+c

Plot: To draw on a graph

Parallel lines: Two lines that never meet. They are always the same distance apart with the same gradient  

Gradient: How steep a line is 

Equation: A Mathematical statement that two things are equal  

Y-intercept: The point where a line or curve crosses the y-axis of a graph