Real values are sequences of digits with a positive or negative sign, like integers. This also makes it possible to specify fraction values:

float realNumber = 12.5f;
realNumber = 1.25e+1f;
double realdNumber = 12.5;

As you can see, the literal in the last line, 12.5 is double by default, hence it needed to be assigned to a double variable, while the first two lines specify the literal in float types. You can also specify d or D as a suffix to define a double, like f or F for float and m for decimal.