What is Special-purpose Entity?

Legal Definition
A special-purpose entity (SPE; or, in Europe and India, special-purpose vehicle/SPV, or, in some cases in each EU jurisdiction – FVC, financial vehicle corporation) is a legal entity (usually a limited company of some type or, sometimes, a limited partnership) created to fulfill narrow, specific or temporary objectives. SPEs are typically used by companies to isolate the firm from financial risk. They are also commonly used to hide debt (inflating profits), hide ownership, and obscure relationships between different entities which are in fact related to each other.

Normally a company will transfer assets to the SPE for management or use the SPE to finance a large project thereby achieving a narrow set of goals without putting the entire firm at risk. SPEs are also commonly used in complex financings to separate different layers of equity infusion. Commonly created and registered in tax havens, SPEs allow tax avoidance strategies unavailable in the home district. Round-tripping is one such strategy. In addition, they are commonly used to own a single asset and associated permits and contract rights (such as an apartment building or a power plant), to allow for easier transfer of that asset. They are an integral part of public private partnerships common throughout Europe which rely on a project finance type structure.

A special-purpose entity may be owned by one or more other entities and certain jurisdictions may require ownership by certain parties in specific percentages. Often it is important that the SPE is not owned by the entity on whose behalf the SPE is being set up (the sponsor). For example, in the context of a loan securitization, if the SPE securitisation vehicle were owned or controlled by the bank whose loans were to be secured, the SPE would be consolidated with the rest of the bank's group for regulatory, accounting, and bankruptcy purposes, which would defeat the point of the securitisation. Therefore, many SPEs are set up as 'orphan' companies with their shares settled on charitable trust and with professional directors provided by an administration company to ensure that there is no connection with the sponsor.
-- Wikipedia
Legal Definition
This structure in business lets companies operate smaller operations without the worry of a large risk financially.