Question

What does it mean to have a positive exponent?

Answer 1

Having a positive exponent means having a positive number as a power for a value or a variable.

For example:
$x^{2}$  
Here, the variable x has a positive exponent because it has a power of positive (+) 2

$\frac{1}{ 2^{4} }$ 
This expression has a positive exponent because the number 1 has a power of positive (+)1 and the number 2 has a power of positive (+)4

$x^{-2}$
This is not a positive exponent because the variable x has a power of negative  (-)2
The positive exponent for $x^{-2}$ is $\frac{1}{ x^{2} }$.

$\frac{1}{ 2^{-4} }$
This expression doesn't have a  positive exponent. Though number 1 in the numerator has a positive power (exponent), the number 2 in the denominator has a power of negative (-)4
The positive exponent for $\frac{1}{ 2^{-4} }$ would be $2^{4}$.

NOTE: The terms Power and Exponent have he same meanine i.e. They are the same !!!