The size of double and long double in floating point data type is same 8 bytes. Then what is difference between them?

Answer 1

long is for integer type data ,mostly 4 bytes
double is for floating point data

Answer 2

This also depends on the compiler. Visual Studio will actually give you a double if you try to use a float. you have to verify that you, indeed, wanted to use a float.

Answer 3

if u observe that table more keenly then you will see that those are MINIMUM size.. long double provide wider range then double.. and thus long double works more precisely! :)

Answer 4

for practical use as a novice, as I understand it, excluding memory points...

int holds whole numbers...
double isn't an int... so can use to hold decimal numbers. :-)