Polynomial Equation: A polynomial equation is an equation that can be written in the form $a_nx^n + a_{n-1}x^{n-1} + \dots + a_1x + a_0 = 0$, where the coefficients $a_i$ are complex numbers.
Complex Numbers:Complex numbers are numbers that can be expressed in the form $a + bi$, where $a$ and $b$ are real numbers and $i$ is the imaginary unit, satisfying $i^2 = -1$.
Roots of a Polynomial: The roots of a polynomial equation are the values of $x$ that make the equation equal to zero. The Fundamental Theorem of Algebra guarantees that every non-constant polynomial has at least one complex root.