Opportunity Cost vs Trade-off

Opportunity cost is the value of the next-best alternative you give up when you make a choice.

Because resources are scarce, every choice means forgoing something else, and economists count only the next-best forgone option. Opportunity cost includes both explicit costs (money paid) and implicit costs (forgone earnings or benefits). This is why economic cost can be larger than simple accounting cost.

A trade-off is the exchange of one thing for another, reflecting the reality that choosing more of one thing means having less of something else.

Trade-offs arise from scarcity - since resources are limited, we can't have everything we want. Individuals, businesses and societies must weigh alternatives and make trade-offs. For example, a student who chooses to study rather than go out with friends is making a trade-off, gaining better grades but giving up leisure time.