What is the line that divides a parabola into two matching halves?

The line that divides a parabola into two matching halves is called the "axis of symmetry." For a standard quadratic equation of the form (y = ax^2 + bx + c), the axis of symmetry can be found using the formula (x = -\frac{b}{2a}). This vertical line passes through the vertex of the parabola and ensures that each side is a mirror image of the other.