This paper deals with the normal modes of the global oceans. More specifically, it reviews some of the work done in association with the modeling, detection, and application of the barotropic, basin-wide normal modes. The paper presents some results obtained by means of the Proudman-Rao method. The fields of tidal synthesis from a set of normal modes, and paleotides, in the context of normal modes and the evolution of the Earth-Moon system, are surveyed as well. Works associated with the detection of normal modes are discussed also. The paper closes with an analysis of possible future developments.