The type of exponent determines how you evaluate the exponential expression.
If the exponent is a positive integer it's equivalent to the base multiplied by itself n times. If the exponent is O, the expression is evaluated as 1. If the exponent is a negative integer it's equivalent to 1 divided by the base multiplied by itself n times.
If the exponent is a rational expression, n/ m, it's equivalent to the mth root of the base raised to thenth power.