The Actual percentage is what you sold to the segment. The Potential is what you deserved to sell to the segment. If none of the products in the segment stock out, these numbers will be the same.

Here is an example: Your Traditional Market Segment report shows Actual sales of 20%. The Potential was only 15%. This means your competitors stocked out and desperate customers turned to your product instead. If the other product had not stocked out, your product would not have gained the additional 5% of sales.

The opposite can hold true as well: Your Potential was 20%, but your Actual was only 15%. This means your product stocked out, and while you could have made additional sales, you had no available inventory.