There are only two outcomes for each flip, that is either heads or tails. Now each flip is independent from the previous one since the flip does not depend on the result of the other flips.
So for the first flip, there are 2 possible outcomes. For the second flip, also 2 possible outcomes, and for the third flip and so on until the eight flip. Therefore the total number of possible outcomes is:
Outcomes = 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2
Or can be written as:
Outcomes = 2^8
Calculating the actual value:
Outcomes = 256
Therefore there are 256 possible outcomes for flipping a coin eight times.