Polynomial long division is a method used to divide one polynomial by another, similar to how long division works with numbers. The process involves dividing the leading term of the dividend by the leading term of the divisor, then multiplying the entire divisor by this result and subtracting it from the dividend. This step is repeated until the degree of the remainder is less than the degree of the divisor. The result of polynomial long division includes a quotient and a remainder. The quotient represents how many times the divisor fits into the dividend, while the remainder is what is left over. This technique is useful in simplifying expressions and solving polynomial equations.