Polynomials are simply functions that you see all the time
A second degree polynomial would look like:
y = ax^2 + bx + c
That is because the largest power is to the 2.
A third degree polynomial would be raised to the third power when it's the biggest number:
y = ax^3 + bx^2 + cx + d
The a, b, c, and d are just variables for any number