For a commutative ring R, we investigate the structural and ideal-theoretic properties of the quotient polynomial ring \(R[x]/\langle x^n \rangle \) for each positive integer n, where R[x] denotes the ring of polynomials in an indeterminate x, and \(\langle x^n \rangle \) is the ideal generated by \(x^n\) . In this paper, we determine the units and the Jacobson radical of \(R[x]/\langle x^n \rangle \) , providing foundational insight into its local structure. Furthermore, we identify necessary and sufficient conditions under which \(R[x]/\langle x^n \rangle \) satisfies various ideal-theoretic properties, including quasi-primary ideals, (quasi) J-ideals, r-ideals, (quasi) n-ideals, 2-absorbing ideals, and 2-absorbing primary ideals. Our results extend and unify numerous existing findings, and illustrative examples are provided to clarify and delimit the theoretical framework.