The range of a function is defined as the possible set of values of "y" the said function can take.
The function on the picture has one horizontal asymptote (this means that it gets close to the x-axis but never touches it) that is above the x-axis, which indicates that the function will always have positive values. For this same reason the range will never be zero.
So the range of the function is all values of y that are greater than zero or all positive real numbers.
