Floating point numbers have several limitations. One of them is the magnitude, which determines the largest and smallest numbers that can be represented. This is largely determined by the exponent. The other is the precision, which is how many places after the decimal point can be represented. In terms of a number line, magnitude limitations determine how far out to the left or right you can go. Precision limitations determine how close each point on that line is to the next point, where these points determine representable numbers and the white space in between is the sequence of non-representable numbers.