An online service provider can, for example, be an Internet service provider, an email provider, a news provider (press), an entertainment provider (music, movies), a search engine, an e-commerce site, an online banking site, a health site, an official government site, a wiki, or a Usenet newsgroup.

In its original more limited definition, it referred only to a commercial computer communication service in which paid members could dial via a computer modem the service's private computer network and access various services and information resources such a bulletin boards, downloadable files and programs, news articles, chat rooms, and electronic mail services.

The term "online service" was also used in references to these dial-up services.

The traditional dial-up online service differed from the modern Internet service provider in that they provided a large degree of content that was only accessible by those who subscribed to the online service, while ISP mostly serves to provide access to the Internet and generally provides little if any exclusive content of its own.

In the U.S., the Online Copyright Infringement Liability Limitation Act (OCILLA) portion of the U.S. Digital Millennium Copyright Act has expanded the legal definition of online service in two different ways for different portions of the law.

It states in section 512(k)(1):

A white label product is a product or service produced by one company (the producer) that other companies (the marketers) rebrand to make it appear as if they had made it.

A desktop computer is a personal computer designed for regular use at a single location on or near a desk or table due to its size and power requirements.

The most common configuration has a case that houses the power supply, motherboard (a printed circuit board with a microprocessor as the central processing unit (CPU), memory, bus, and other electronic components), disk storage (usually one or more hard disk drives, optical disc drives, and in early models a floppy disk drive); a keyboard and mouse for input; and a computer monitor, and, often, a printer for output.

The case may be oriented horizontally or vertically and placed either underneath, beside, or on top of a desk.