The algebraic structure and the relationships between the eigenspaces of th
e Calogero-Sutherland model (CSM) and the Sutherland model (SM) on a circle
are investigated through the Cherednik operators. We find an exact connect
ion between the simultaneous nonsymmetric eigenfunctions of the A(N-1) Cher
ednik operators, from which the eigenfunctions of the CSM and SM are constr
ucted, and the monomials. This construction allows us to simultaneously dia
gonalize both CSM and SM (after gauging away the Hamiltonians by suitable m
easures) and also enables us to write down a harmonic oscillator algebra in
volving the Cherednik operators, which yields the raising and lowering oper
ators for both of these models. The connections of the CSM with free oscill
ators and the SM with free particles on a circle are established in a novel
way. We also point out the subtle differences between the excitations of t
he CSM and the SM.