A ConnectionString is a text string used to connect to a resource.
For example, a ConnectionString to a relational database might contain the database server software name, the server name, the database (catalog) name, a user id, and a password.
A ConnectionString is a convenient hook to distinguish between a production database and a TestDatabase.
And so, if you add a little rum and coke, everything should work fine, so long as you're not dealing with a NoStrings purist.
See also: TestDatabase