Internet/Introduction

The Internet is the worldwide "network of networks" that links millions of computers together via copper wires, fiber-optic cables, wireless connections, and other telecommunications channels. This publicly accessible network of interconnected computer networks communicate using a set of protocols and standards, the most basic of which are TCP/IP.

The Internet and the World Wide Web are everywhere. They can provide answers to questions and hours of entertainment. The Internet can allow people from all over the world to talk to each other. But what exactly are the Internet and the World Wide Web?

This resource is intended to function as a general overview of the workings of the Internet, which may cover social, economic, historical and other aspects. For a more detailed and step by step approach to learning about networking, consider visiting the topic on computer networking.

History

See History of the Internet at Wikipedia

The internet started out as a US Department of Defence project called ARPANET, which slowly expanded with the integration of packet switching networks over circuit switching networks. ARPANET could be considered the original heart of the internet, with additional bits and pieces being added on until certain standards were needed to unify them all. These standards eventually came to be known as Protocols.

As of July 2008, there were close to 600 million hosts connected to the World Wide Web, linked together by a series of switches and communication links.

Protocols

A protocol is a definition of the format and order of messages that are exchanged between two or more hosts. For example, if person A wanted to know the time from person B in England, person A may approach person B and ask "What is the time?". Person B may then reply with the current time. Some important things to note in this example is that both assume they will be communicating in English, and have a concept of time. While these are things that we as human beings may take for granted, machines have no idea what and how they will be communicating with each other until a set of rules is specified. As mentioned above, one of the most original and common protocols in use today is the TCP/IP protocol.

TCP/IP consists of the Transmission Control Protocol in conjunction with the Internet Protocol. Other protocols such as DHCP, DNS, FTP, HTTP, IRC, MIME, POP3, SMTP, SSH, TELNET, RTP and many more help hold the whole thing together.

Protocols are only a subset of the entire design of the internet. Proposals for existing and new standards are made through Requests for Comments (RFCs), hosted by the Internet Engineering Task Force. RFCs are highly technical and detailed documents that specify each and every operation of the standard being proposed. Comments (hence the name) are sought after regarding the standard and the process carries on until most are satisfied. The standard is then published.

OSI Model

A popular way to visualize the complexity of the Internet is to see it as a stack of layers known as the OSI model, short for Open Systems Interconnection model.

OSI Layers:

• Layer 7: Application Layer – the main interface for the user(s) to interact with the application and therefore the network
• Layer 6: Presentation Layer – transforms data to provide a standard interface for the Application layer
• Layer 5: Session Layer – controls the dialogues (sessions) between computers
• Layer 4: Transport Layer – provides transparent transfer of data between end users and machines
• Layer 3: Network Layer – provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks
• Layer 2: Data Link Layer – provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the physical layer
• Layer 1: Physical Layer – defines all the electrical and physical specifications for devices and the communications media

See OSI model at Wikipedia

World-Wide Web Consortium

W3.org The World Wide Web Consortium (W3C) is the main international community where member organizations, a full-time staff, and the public work together to develop Web standards. Without standards, the Internet would never have worked. All sorts of ways to learn, and get involved in using and advancing web technology have been provided. See W3C Developers page, for starters. Even though a few governments and corporations will sometimes try to dominate the Internet, its design insures a fully open and transparent participation process. Anyone may request an account.

IETF and ISOC

The Internet Engineering Task Force has been a key driver of the Internet's technical development since the beginning. From IETF RFC3935 (Alvestrand 2004):

 The Internet: A large, heterogeneous collection of interconnected
     systems that can be used for communication of many different types
     between any interested parties connected to it.  The term includes
     both the "core Internet" (ISP networks) and "edge Internet"
     (corporate and private networks, often connected via firewalls,
     NAT boxes, application layer gateways and similar devices).  The
     Internet is a truly global network, reaching into just about every
     country in the world.
     The IETF community wants the Internet to succeed because we
     believe that the existence of the Internet, and its influence on
     economics, communication, and education, will help us to build a
     better human society.

New Participants are encouraged to read The Tao of IETF: A Novice's Guide to the Internet Engineering Task Force. The IETF is ostensibly for the technological side of things. For the social, administrative, political and ideological side of things, the IETF encourages participation in its governing organization, the Internet Society - Internet Society (ISOC)

Learning projects

• Computer Science
• Software Engineering
• Computer Networks
• Web Design
• Introduction to Computers/Internet

See also

• w:Internet
• w:Internet#Internet_by_region