Having a positive exponent means having a positive number as a power for a value or a variable.
For example:
[tex] x^{2} [/tex]
Here, the variable x has a positive exponent because it has a power of positive (+) 2
[tex] \frac{1}{ 2^{4} } [/tex]
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
[tex] x^{-2} [/tex]
This is not a positive exponent because the variable x has a power of negative (-)2
The positive exponent for [tex] x^{-2} [/tex] is [tex] \frac{1}{ x^{2} } [/tex].
[tex] \frac{1}{ 2^{-4} } [/tex]
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 [tex] \frac{1}{ 2^{-4} } [/tex] would be [tex]2^{4} [/tex].
NOTE: The terms Power and Exponent have he same meanine i.e. They are the same !!!