A point inside the production possibilities frontier is feasible, but not efficient.
Production possibility frontier of a country is the point at which a country's economy is most efficient in producing its goods services and therefore allocating and using it's resource at its best possible way.
Production possibility frontier curve shows different combinations or collections of the amount of quantity of two goods which can be produced within the given resources and technology. It explains several economic concepts such as allocating efficiency, economies of scale, opportunity cost, production efficiency and scarcity of resources.