Hello!
The variable "n" represents an exponent.
An exponent is used to multiply a number (b) by itself "n" times. For example, if the expression were to read (b²) it would represent the following:
b × b
The same could be said for (b³):
b × b × b
Even ([tex] b^{10} [/tex]):
b × b × b × b × b × b × b × b × b × b
I hope this helps!