Where are the default parameters defined NLS in Oracle

SELECT * FROM nls_session_parameters;
SELECT * FROM nls_instance_parameters;
SELECT * FROM nls_database_parameters;

PARAMETER                      VALUE
------------------------------ ----------
NLS_LANGUAGE                   AMERICAN
NLS_TERRITORY                  AMERICA
NLS_CURRENCY                   $
NLS_ISO_CURRENCY               AMERICA
NLS_NUMERIC_CHARACTERS         .,
NLS_DATE_FORMAT                DD-MON-YY
NLS_DATE_LANGUAGE              AMERICAN
NLS_CHARACTERSET               WE8ISO8859
NLS_SORT                       BINARY
NLS_CALENDAR                   GREGORIAN
NLS_RDBMS_VERSION              7.3.4.4.0