The purpose of this paper is to investigate the duality between large scale and small scale. It is done by creating a connection between C*-algebras and scale structures. In the commutative case we consider C*-subalgebras of C b (X), the C*-algebra of bounded complexvalued functions on X. Namely, each C*-subalgebra C of C b (X) induces both a small scale structure on X and a large scale structure on X. The small scale structure induced on X corresponds (or is analogous) to the restriction of C b (h(X)) to X, where h(X) is the Higson compactification. The large scale structure induced on X is a generalization of the C 0 -coarse structure of N.Wright. Conversely, each small scale structure on X induces a C*-subalgebra of C b (X) and each large scale structure on X induces a C*-subalgebra of C b (X). To accomplish the full correspondence between scale structures on X and C*-subalgebras of C b (X) we need to enhance the scale structures to what we call hybrid structures. In the noncommutative case we consider C*-subalgebras of bounded operators B(l 2 (X)).