8x^4
(8x)4
An exponent.
The exponent.
5x5x5
3x^6
5x^3
a^17 x b^14 where ^ means "raised to the power of.."
The base is the repeated factor. The exponent tells how many times the base is repeated.
2 x 2 x 2 x 2 x n = 8n
The base
The base.
The exponent tells the number of times the base is to be used as a factor.
A number used as a factor two times is a square root.