The VizieR database is a collection of astronomical catalogues standardized for uniform access and use. It was developed by the Centre de Données de Strasbourg (CDS) and other institutions to manage and provide access to thousands of astronomical catalogues. The system allows users to query these catalogues through various interfaces, including the ASU protocol and XML. The database includes a meta-dictionary that describes the structure and content of each catalogue, enabling efficient data retrieval and processing. The system also handles large catalogues by using specialized methods for storage and access. VizieR supports links between catalogues and external services, facilitating data integration and analysis. The database has grown significantly, with over 3,000 catalogues available, and continues to expand. The system is designed to be interoperable, allowing data from different sources to be combined and analyzed. The standardized documentation of catalogues ensures that data is accessible and usable by astronomers, even those unfamiliar with the original instruments. VizieR plays a key role in data mining and cross-correlation projects, supporting research in astronomy and related fields. The system is continually developed to improve its functionality and accessibility.The VizieR database is a collection of astronomical catalogues standardized for uniform access and use. It was developed by the Centre de Données de Strasbourg (CDS) and other institutions to manage and provide access to thousands of astronomical catalogues. The system allows users to query these catalogues through various interfaces, including the ASU protocol and XML. The database includes a meta-dictionary that describes the structure and content of each catalogue, enabling efficient data retrieval and processing. The system also handles large catalogues by using specialized methods for storage and access. VizieR supports links between catalogues and external services, facilitating data integration and analysis. The database has grown significantly, with over 3,000 catalogues available, and continues to expand. The system is designed to be interoperable, allowing data from different sources to be combined and analyzed. The standardized documentation of catalogues ensures that data is accessible and usable by astronomers, even those unfamiliar with the original instruments. VizieR plays a key role in data mining and cross-correlation projects, supporting research in astronomy and related fields. The system is continually developed to improve its functionality and accessibility.