MDAC 2.5 SDK - OLE DB Programmer's Reference
Chapter 20: OLE DB Core Components

Connection Strings and Data Links

A data link enables you to easily store connection information within an application or to pass it between applications. The format of a data link is a connection string, which is a string version of the initialization properties needed to connect to a data store. Without a connection string, it would be necessary to store or pass a complex array of structures to access data.

In some cases, it might be desirable to manually build a connection string within an application. Therefore, it is important that the Connection String Syntax adhere to the formatting rules.