Purchase and sale agreements can generally be divided into those used in public transactions (i.e. where the target, and possibly the acquirer, is a public entity) and those used in private transactions (i.e. the sale of a private company, a subsidiary, or selected assets of a public entity). The distinction is important because, in the sale of a public entity, there will be no continuing party to which the acquirer may have legal recourse for breaches under an indemnification (i.e. all representations and warranties expire at closing).
For example, if there are large environmental liabilities that a private seller has failed to disclose to the buyer, the buyer may be able to claim compensation for these liabilities subject to the terms of the purchase agreement that indemnify the buyer for such liabilities. However, if the target is a public company, such recourse will not be available to the buyer because it would be impossible to claim compensation from thousands of disparate selling shareholders.