Linked Servers allows us to connect to other database instances on the same server or on another machine or remote servers. It allows SQL Server to execute SQL scripts against OLE DB data sources on remote servers using OLE DB providers.
After setting up the Linked Servers we can easily access the other server tables, procedures etc.
Once the connection is established, we can start with the CRUD operations. The advantage is about security; its works on Windows as well as SQL Server Authentications.
In Sql Server we refer as linked servers and in Oracle we refer them as database links.