more useful information extracted from the cited book
- numeric(precision, scale) = decimal(precision, scale) - Exact Numeric Data Types
- real = float(24) - Approximate Numeric Data Types
- All exact numeric types always produce the same result, regardless of which kind of processor architecture is being used or the magnitude of the numbers
- The parameter supplied to the float data type defines the number of bits that are used to store the mantissa of the floating point number.
source :
MCTS Self-Paced Training Kit (Exam 70-433): Microsoft® SQL Server® 2008 Database Development
Chapter 3 - Tables , Data Types , and Declarative Data Integrity Lesson 1
Choosing Data Types (Guidelines) - Page 93
