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For more about specific sources see ETL+ Source Types
For even more technical information about each source type see Source Systems and IT
About ODBC data sources
A [ODBC] data source is a source of data combined with the connection information that is required to access that data. Examples of data sources are SQL Server, Oracle RDBMS, a spreadsheet, and a text file. Examples of connection information include server location, database name, logon ID, password, and various ODBC driver options that describe how to connect to the data source. This information can be obtained from the administrator of the database to which you want to connect.