What is the name of the attribute for exponential functions,where the function gets close to it but never touches it?

Answer:
the graph gets close to the x-axis but never touches it.
Step-by-step explanation:
An exponential function is a function of the form [tex]f(x)=a^x[/tex]
Here, [tex]a>0[/tex]
The value of this function is always greater than 0.
The exponential function gets close to the x-axis but never crosses it.
It intersects the y-axis at the point [tex](0,1)[/tex].
Domain of the exponential function is a set of real numbers.
Range is [tex](0,\infty )[/tex]