Coefficients are the numbers infront of a varible. A polynominal can only use addition, subtraction, multiplication (doesn't have to use all of them). The exponents of a polynominal cannot be negative. Normally they are in the form \(ax^2 + bx +c\) but doesn't have to be.
Examples: x^2 + 2x +5,
5x +1
(x^7 + 2x^4 - 5) * 3x