If a recessionary gap is to an economy's inefficiency, then a production possibilities frontier (PPF) is to what?

A recessionary gap happens when an economy is not producing as much as it could, meaning there are unused resources like workers and factories. Similarly, a production possibilities frontier (PPF) represents the maximum output an economy can achieve with its available resources. Just as a recessionary gap shows inefficiency, the PPF illustrates the limits of production efficiency for an economy. For example, if a country can produce either 100 cars or 200 bikes but only makes 50 cars and 50 bikes, it is not using its resources efficiently, much like how a recessionary gap indicates underutilization. Therefore, both concepts highlight the importance of using resources fully to achieve better outcomes.