Public Internet

Worldwide Internet users

	2005	2010	2016a
World population	6.5 billion	6.9 billion	7.3 billion
Users worldwide	16%	30%	47%
Users in the developing world	8%	21%	40%
Users in the developed world	51%	67%	81%
a Estimate. Source: International Telecommunications Union.

Network Architecture	Service Model	Guarantee ?				Congestion Feedback
		Bandwidth	Loss	Order	Timing
Internet	best effort	none	no	no	no	no (inferred via loss)
ATM	CBR	constant rate	yes	yes	yes	no congestion
ATM	VBR	guarantee rate	yes	yes	yes	no congestion
ATM	ABR	guarantee minimum	no	yes	no	yes
ATM	UBR	none	no	yes	no	no

The Internet is the global system of interconnected computer networks that use the (TCP/IP) to link devices worldwide. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing.

The origins of the Internet date back to research commissioned by the United States federal government in the 1960s to build robust, fault-tolerant communication via computer networks. The linking of commercial networks and enterprises in the early 1990s marks the beginning of the transition to the modern Internet, and generated rapid growth as institutional, personal, and mobile computers were connected to the network. By the late 2000s, its services and technologies had been incorporated into virtually every aspect of modern life.

Most traditional communications media, including telephony, radio, television, paper mail and newspapers are being reshaped or redefined by the Internet, giving birth to new services such as email, Internet telephony, Internet television, online music, digital newspapers, and video streaming websites. Newspaper, book, and other print publishing are adapting to website technology, or are reshaped into blogging, web feeds and online news aggregators. The Internet has enabled and accelerated new forms of personal interactions through instant messaging, Internet forums, and social networking. Online shopping has grown exponentially both for major retailers and small businesses and entrepreneurs, as it enables firms to extend their "brick and mortar" presence to serve a larger market or even sell goods and services entirely online. Business-to-business and financial services on the Internet affect supply chains across entire industries.

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Wikipedia