A service provider (SP) is a company that provides organizations with consulting, legal, real estate, education, communications, storage, processing, and many other services. Although the term service provider can refer to organizational sub-units, it is more generally used to refer to third party or outsourced suppliers, including telecommunications service providers (TSPs), application service providers (ASPs), storage service providers (SSPs), and Internet service providers (ISPs). IT professionals sometimes differentiate between service providers by categorizing them as type I, II, or III. The three service types are recognized by the IT industry although specifically defined by ITIL and the US Telecommunications Act of 1996 Type I: internal service provider Type II: shared service provider Type III: external service provider Type III SPs provide IT services to external customers and subsequently can be referred to as external service providers (ESPs) which range from a full IT organization/service outsource via managed services or MSPs (managed service providers) to limited product feature delivery via ASPs (application service providers).