A database link (DB link) in Oracle is a way to connect to a remote database and access its data as if it were local. This allows you to share data between different databases, or to access data from a different database without having to copy it locally.
DB links are created using the CREATE DATABASE LINK statement. The statement specifies the name of the DB link, the remote database to connect to, and the credentials to use for the connection. Once a DB link has been created, you can use it to query data from the remote database using the standard SQL syntax. For example, the following query would return all of the customers from the remote database:
