What is a vector? In mathematics, a vector is a line segment that has both magnitude and direction. This means that in addition to being a certain length (magnitude) the segment is also pointed in a certain direction going from the initial point (starting point) to the terminal point (ending point). This direction is represented by an angle in degrees or radians relative to the x-axis on the coordinate plane and can be found using the Pythagorean theorem. Vectors are useful to represent many real life occurrences such as the location and direction of flight of an airplane or even the migration of a marine animal spotted on sonar. The possibilities are endless!