Getting Help Information on Configuration Parameters

Use either sp_helpconfig or sp_configure to display information about a particular configuration parameter.

For example:
sp_helpconfig "number of open"
Configuration option is not unique.
option_name                    config_value  run_value
------------------------------ ------------ -----------
number of open databases                 12          12
number of open indexes                  500         500
number of open objects                  500         500
sp_helpconfig "number of open indexes"
number of open indexes sets the maximum number of indexes that can be open at
one time on SQL Server. The default value is 500.
Minimum Value Maximum Value Default Value Current Value Memory Used
------------- ------------- ------------- ------------- -----------
          100    2147483647           500            500         208
sp_configure "number of open indexes"
Parameter Name           Default  Memory Used  Config Value  Run Value
-----------------------  -------  -----------  ------------  ---------
number of open indexes       500          208           500        500

See System Administration Guide: Volume 2 > Configuring Memory.