A linked server in Microsoft SQL Server is a connection between your SQL Server instance and an external data source, enabling access to data from various sources as if it were part of your primary database. This feature allows for consolidated data access, distributed transactions, enhanced performance, but also introduces security considerations, potential performance overhead, and complexity. To create a linked server, you need to define the remote data source, assign a server name, configure authentication settings, and comprehend the security context associated with the login on the remote server. Linked servers can be used for querying smaller datasets, ETL processes, alternative data integrations, accessing different data sources, and federated queries. CData provides a robust solution for connecting any ODBC data source as a linked server, offering seamless integration, data accessibility, and interoperability.