Difference between numeric, float and decimal in SQL Server

Question

What are the differences between numeric, float and decimal datatypes and which should be used in which situations?

For any ki

Answer 1

Decimal has a fixed precision while float has variable precision.

EDIT (failed to read entire question): Float(53) (aka real) is a double-precision (64-bit) floating point number in SQL Server. Regular Float is a single-precision (32-bit) floating point number. Double is a good combination of precision and simplicty for a lot of calculations. You can create a very high precision number with decimal -- up to 136-bit -- but you also have to be careful that you define your precision and scale correctly so that it can contain all your intermediate calculations to the necessary number of digits.