In Thomas Sowell's book titled, "Basic Economics", he says the following:

"Unmet needs" are inherent in these circumstances, whether we have a capitalist, socialist, feudal, or other kind of economy. These various kinds of economies are just different institutional ways of making trade-offs that are inescapable in any economy.

He has been talking about what scarcity means and what it implies -

It means (Scarce) that what everybody wants adds up to more than there is. What this implies is that there are no easy "win-win" solutions but only serious and sometimes painful trade-offs.

In a real world context, what would be some big trade-offs that the U.S., specifically, has made? And, what have been some consequences or maybe some pros of those decisions?

The reason I am asking this is because I can't really 'picture' what exactly a trade-off is.

Thanks for your time!