A vector notation symbol placed above text to indicate directed line segments or vectors between points A and B.
Examples
Vector between two points
\overrightarrow{AB} = (x_2-x_1, y_2-y_1)
Vector addition in geometry
\overrightarrow{AC} = \overrightarrow{AB} + \overrightarrow{BC}
Vector magnitude equation
|\overrightarrow{PQ}| = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}