In math an exponent is what is used to express what a number is being "raised" to. For example has an exponent of 2 so that means that x is actually x multiplied by x. It is an easier way of writing math when you need to multiply by the same number. Another example could be . This is saying 2 to the fifth power which is just
2 x 2 x 2 x 2 x 2 but having an exponent makes it easier to write in a math problem than multiplying two by two five consecutive times.