Answer:
The base is 5
The exponent is 4

And the value is 625
Explanation:
Exponentials
If a number is multiplied by itself n times like shown below:

It can be written in exponential form:

Where x is the base and n is the exponent.
In the expression:

The base is 5
The exponent is 4
Writing the expression using an exponent:

And the value is 625