A more thorough explanation:

A quasi-corporation, also known as a civil corporation, is an entity that performs some functions and holds some properties that are traditionally associated with corporations, but it is not incorporated like a general business. Examples of quasi-corporations include counties, school districts, and state agencies.

Like corporations, quasi-corporations may have boards that make decisions for the entity. However, there are generally limitations on what type of actions may be brought against them. For example, quasi-corporations are generally shielded from civil liability and private action for negligence in the performance of their public duties, except in circumstances when such private actions are expressly permitted by statute.

The rationale behind this limitation on liability is that quasi-corporations generally exist to serve some form of public interest. Furthermore, some quasi-corporations, such as civil divisions or agencies of the state, are sometimes established involuntarily for the purpose of assisting the state in conducting local administration. As a result, because they are involuntarily created for the benefit of the public and not necessarily the people who run them, some quasi-corporations are shielded from certain modes of liability in the same manner as the state government.

For example, a board of education, established by the state, is a quasi-corporation that owns no property, no private corporate interests, and derives "no special benefits from its corporate acts." As an agency established for the sole purpose of carrying out the state's administration of public education, it enjoys the same protection from liability as the state itself.