Exponents:

The product a x a x a x a can be written as a⁴, where 4 is called the exponent of a or power to which a is raised.  In this notation, a is frequent called the base.

Examples:

a⁴ = a. a. a. a

5³ = 5. 5. 5

(a + b)⁵ = (a+b) . (a+b) . (a+b) . (a+b). (a+b)

While an exponent is not written, it is supposed to be 1. For example, a¹ = a.   An exponent applies only to the quantity immediately to the left and below it. For example, in 3 + (-2)³ the base is -2, but in 3 - 2³ the base is 2.