Public Goods:Goods or services that are non-rival and non-excludable, meaning their consumption by one individual does not reduce their availability for others, and it is difficult to prevent people from using them.
Market Failure: A situation where the free market fails to allocate resources efficiently, leading to a suboptimal outcome for society as a whole.
Tragedy of the Commons:A situation where individuals, acting independently and rationally according to their own self-interest, will ultimately deplete or destroy a shared resource, even when it is not in anyone's long-term interest for this to happen.