A Data Source Name associates the configuration parameters for communicating with a specific database. Generally, a DSN consists of the following parameters:
In addition, different ODBC drivers, including Connector/ODBC, may accept additional driver-specific options and parameters.
There are three types of DSN:
A System DSN is a global DSN definition that is available to any user and application on a particular system. A System DSN can normally only be configured by a systems administrator, or by a user who has specific permissions that let them create System DSNs.
A User DSN is specific to an individual user, and can be used to store database connectivity information that the user regularly uses.
A File DSN uses a simple file to define the DSN configuration. File DSNs can be shared between users and machines and are therefore more practical when installing or deploying DSN information as part of an application across many machines.
DSN information is stored in different locations depending on your platform and environment.