The size of the Instant Client Basic Light library is smaller than Oracle Instant Client. This is because Instant Client Basic Light contains only English language error message files and only a few supported character set definitions out of around 250.

The Instant Client Basic Light version is geared toward applications that use either Unicode, ASCII, and Western European character set support. There is no restriction on the LANGUAGE and the TERRITORY fields of the NLS_LANG setting, hence, Instant Client Basic Light operates with any language and territory settings. Only English error messages are provided with Instant Client Basic Light, hence, error messages generated by the client, such as Net connection errors, are always reported in English, even if you set NLS_LANG to a language other than AMERICAN. Error messages generated by the database server, such as SQL statement syntax errors, are generated in the selected language provided that you install the appropriate translated message files in the Oracle home of the database instance.