Final answer:
A production possibilities frontier (PPF) provides an illustration of the principle that trade-offs are unavoidable.
Step-by-step explanation:
A production possibilities frontier (PPF) provides an illustration of the principle that trade-offs are unavoidable. The PPF shows the different combinations of goods and services that society can produce given its available resources and technology. The shape of the PPF is typically curved outward, indicating that as more of one good is produced, the opportunity cost of producing additional units increases. Choices outside the PPF are unattainable, while choices inside the PPF are considered inefficient or wasteful.