A polynomial root is a value of the variable that makes the polynomial equal to zero. For example, in the polynomial f(x) = x² - 4, the roots are x = 2 and x = -2 because substituting these values into the equation results in zero. Finding roots is essential in various fields, including mathematics and engineering. Roots can be real or complex numbers. Real roots are points where the graph of the polynomial intersects the x-axis, while complex roots occur in pairs and do not intersect the x-axis. Understanding polynomial roots helps in solving equations and analyzing functions.