The Free On-line Dictionary of Computing (19 January 2023):

Internet Service Provider
Internet provider

    (ISP) A company which provides other
   companies or individuals with access to, or presence on, the
   Internet.  Most ISPs are also Internet Access Providers;
   extra services include help with design, creation and
   administration of websites, training and
   administration of intranets and domain name registration.

   (2005-06-19)