difference between float and [numeric](18, 10)

Question

what's the differece between a sql server type of:

float and [numeric](18, 10)

Answer 1

FLOAT conforms to IEEE 754 and approximates decimal representation.

NUMERIC is exact in decimal representation (up to the declared precision).

SELECT  CAST(PI() AS FLOAT),
        CAST(PI() AS NUMERIC(20, 18)),
        CAST(PI() AS NUMERIC(5, 3))


---------------------- --------------------------------------- ---------------------------------------
3,14159265358979       3.141592653589793100                    3.142