Embed some combinatorial problem into a vector space.

Capture the hypotheses of the problem by constructing a polynomial of low-degree that is zero on a certain set

After constructing the polynomial, argue about its algebraic properties to deduce that the original configuration must satisfy the desired properties.

The [3] by Dvir

finite field Kakeya conjecture

The problem by Ellenberg and Gijswijt[7] with the original framework developed on the analogous problem over by Croot, Lev and Pach[8]

cap set

The by Guth and Katz[4]

Erdős distinct distances problem

The Joints Problem in 3D by Guth and Katz. Their argument was later simplified by Elekes, Kaplan and Sharir[10]

[9]

A few examples of longstanding open problems that have been solved using the polynomial method are:

Combinatorial Nullstellensatz

by Terence Tao

Survey on the Polynomial Method

by Larry Guth

Survey on the Polynomial Method