The expression $$ax^2 + bx + c$$ represents a quadratic polynomial where 'a', 'b', and 'c' are constants, and 'x' is the variable. In this polynomial, 'a' determines the degree of the quadratic term, 'b' is the coefficient of the linear term, and 'c' is the constant term. Understanding this structure is essential for factoring trinomials and solving quadratic equations.