anything of value that a society has, whether it produced the thing or not, and whether the thing is traded commercially or not.
For example the USA has natural gas (which it did not produce), air (which it did not produce), computers (which it did produce) and personal freedom (which it did produce). Air and personal freedom are not tradeable goods; it's not possible to establish ownership rights for air or freedom.
Philosophers believe that the proper distribution of social goods is still an open question, even if the distribution of economic goods (like computers) is not.
An inequality in the basic structure must always be justified to those in the disadvantaged position. This holds whatever the primary social good and especially for liberty.
John Rawls, *A Theory of Justice*, p.201