Recent advances in spectrometers at both optical and radio wavelengths have tremendously increased the efficiency with which surveys of the redshifts (Doppler shifts) of large numbers of galaxies can be conducted. Such surveys can follow quite different strategic and technical directions, covering with different degrees of completeness one-, two-, or three-dimensional volumes of the universe. First-order application of the redshift-distance relation (Hubble’s law) allows the analysis of the large-scale distribution of galaxies. Comparison of the observed redshifts with those expected on the basis of other distance estimates allows mapping of the gravitational field and the underlying density distribution. Estimation of the many inherent selection biases and instrumental limitations is critical in understanding how our view of the universe is affected by our observational perspective and by the way information is received by current technologies. Special topics include the estimation of the characteristic clustering scales, the topological description of the galaxy distribution, and the evaluation of substructure in the regions of highest galaxy density (clusters), as well as the construction of a true three-dimensional picture of the distribution of both visible and nonluminous matter.