[en] A data management system is generalized when it provides a user-oriented command language for all different functions, applicable to any new data base regardless of its internal organigation, thus removing the need to write new data handling programs for each new data management systems (GDMS) are exposed: data independence of user programs, updating facilities, data retrieval, control of redundancy between data. The hierarchical structure within a single record, the hierarchies of records, the network structures, the relational data bases and the physical storage of data are also presented. Two examples (INFOL and CODASYL systems) and future GDMS development are finally exposed