How did the notion of the freedom of contract create opportunities and constraints on liberty?

Answer 1

Freedom of contract is an underpinning of libertarian government philosophy. It means the you or your group (a corporation or other kind of group) can contract with others without government interference. You can set your own terms for that contract, such as to provide a buyer with firewood in a certain quantity for a certain price on such and such a date, etc., or to work for a big corporation for such-and-such wages, etc. Or you or the group may choose not to enter into any contract with you at all (or with each other).

The restrictions are set by the terms of the contract. The buyer of that firewood cannot refuse to pay you the agreed-upon price, for example, just because he or she decides she doesn't want to. A contract is enforceable under civil law, so it is not without restrictions.

Certain laws may apply, too. I may engage to cater a dinner for your group, but health regulations may apply to my kitchen, so such a contract may be illegal if I don't meet the legal requirements to be a caterer.

I don't know what else your teacher/class might define as restrictions. Make sure you read your text materials carefully.