A data type is an attribute that specifies the type of data that the object can hold: integer data, character data, monetary data, date and time data, binary strings, and so on. In SQL Server 2005, each column, local variable, expression, and parameter has a related data type. Data types in SQL Server 2005 are organized into the following categories:

* Exact Numerics - BIGINT, INT, SMALLINT, TINYINT, BIT, DECIMAL, NUMERIC, MONEY, and SMALLMONEY.

* Approximate Numerics - FLOAT, and REAL.

* Date and Time - DATETIME and SMALLDATETIME.

* Character Strings - CHAR, VARCHAR, and TEXT.

* Unicode Character Strings - NCHAR, NVARCHAR, and NTEXT

* Binary Strings - BINARY, VARBINARY, and IMAGE.

* Other Data Types - CURSOR, SQL_VARIANT, TABLE, UNIQUEIDENTIFIER, TIMESTAMP, and XML.