Database Configuration Assistant - Oracle 10g/11g Data and Database Management Utilities - page 276

Database Character Set : This parameter determines the encoding schema used to
display characters on the screen. The character set determines what languages can
be represented in the database. This is used for data stored in CHAR , VARCHAR , CLOB
and LONG datatypes, identifiers and PL/SQL variables, and SQL/PLSQL source
code storage.
National Character Set : The National Character Set is used to store Unicode
characters in a database that does not have a Unicode character set.
Default Language : This parameter determines the NLS_LANGUAGE instance
parameter, this parameter specifies day and month abbreviations, symbols for A.M.
and P.M., SQL Ordering, writing direction, and other locale parameters derived from
the language.
Default Date Format : This specifies which regional convention will be used to
display the date format. It specifies the NLS_DATE_FORMAT instance parameter value.
Even if these last two parameters have been defined here, they can be redefined later
at instance, session or command level.
Connection mode
Here you can specify either a dedicated or a shared server connection mode. By
default the dedicated server mode is chosen. In a dedicated server environment a
single Oracle server process is dedicated for each user connected to the database.
In a Shared Server connection mode a more complex architecture is defined. The
Oracle server is shared among several processes, this connection mode is advised in
OLTP environments as this allows more scalability; the dedicated mode is advised
for DSS environments and it is required for SYS connections. You can always use
both connection modes. The modes are not mutually exclusive, and this screen only
defines the default connection mode.
Database storage
The final stage of database definition shows how the database structure will be built.
It shows the datafile, controlfile, and redo log file names and locations.