  For any smooth complex projective variety X and smooth very ample
hypersurface Y in X, we develop the technique of genus zero relative
Gromov-Witten invariants of Y in X in algebro-geometric terms. We prove an
equality of cycles in the Chow groups of the moduli spaces of relative stable
maps that relates these relative invariants to the Gromov-Witten invariants of
X and Y. Given the Gromov-Witten invariants of X, we show that these relations
are sufficient to compute all relative invariants, as well as all genus zero
Gromov-Witten invariants of Y whose homology and cohomology classes are induced
by X.
