A computer network that uses standard Internet Protocol (IP) to transmit data through packet switching. It is a "network of networks", which consists of millions of smaller family, academic, commercial and government networks. These networks together carry various information and services, such as e-mail, online chat, file transfer, and Internet pages and other resources of the World Wide Web (WWW).
history
create
The launch of the Soviet satellite prompted the United States to establish the Advanced Research Projects Agency (ARPA) in February, 2008 1958, in order to regain its technological leadership. [1][2] ARPA has set up the Information Processing Technology Office (IPTO) to further study the semi-automatic ground environment (SAGE) plan, which is the first time to connect radar systems nationwide. J. C. R. Licklider was elected as the leader of IPTO, and he believed that the universal network was a potential unified human revolution.
After becoming interested in information technology, Licklider transferred from the psychoacoustic laboratory of Harvard University to MIT in 1950. At MIT, he served on a committee that established Lincoln Laboratory and participated in the SAGE project. 1957, he became the vice president of BBN company, where he bought the first PDP- 1 computer for production and publicly demonstrated the time-sharing operation for the first time.
In IPTO, Licklider hired Lawrence Roberts to lead a project to implement the network. Roberts built this technology on the work of Paul Baran. [Need to quote] He wrote a detailed research report for the US Air Force, suggesting that packet switching (rather than circuit switching) should be used to make the network highly robust and survivable. After a lot of work, the first two nodes that later became ARPANET were interconnected on1October 29th between UCLA in Menlo Park, California and Stanford Institute of International Studies, 1969. ARPANET is one of the "eve" networks of the Internet. Following the demonstration that packet switching works on ARP ANET, the UK Post Office, Telenet, DATAPAC and TRANSPAC cooperated to create the first international packet switching network service. In Britain, this is called International Packet Stream Service (IPSS) in 1978. The network collection based on X.25 has developed from Europe and the United States to cover Canada, Hong Kong and Australia 198 1. Around 1976, X.25 packet switching standard was developed in CCITT (now called ITU-T). X.25 is independent of TCP/IP protocols, which were produced by DARPA's experimental work on ARPANET, packet radio network and packet satellite network at the same time. Vinton Cerf and robert kahn developed the first description of TCP during 1973, and published a paper on this subject in May 1974. The use of the term "Internet" to describe a single global TCP/ IP network began with the publication of 19741February RFC 675, the first complete specification of TCP, written by Vinton Cerf, Jorgen Darla and Carl Sanson at Stanford University at that time. In the next nine years, people continue to improve these protocols and implement them on various operating systems.
When all the hosts on ARPANET are converted from the old NCP protocol to the TCP/IP protocol, the first TCP/IP WAN starts running on 1 month 1, 1983. In 1985, the National Science Foundation (NSF) commissioned the construction of a 56 kilobit/s network backbone of a university, and the computer used was called "fuzzballs" by the inventor David L. Mills. The following year, NSF sponsored the development of a higher-speed 1.5 Mbit/s backbone network, which became NSFNet. Dennis Jennings was in charge of the supercomputer project of the National Science Foundation, and he made a key decision to use the DARPA TCP/ IP protocol.
The opening of the Internet to commercial interests began at 1988. The Federal Network Committee of the United States approved the interconnection between NSFNET and commercial MCI mail system that year, and established the connection in the summer of 1989. Other commercial e-mail services were quickly connected, including OnTyme, Telemail and Compuserve. In the same year, three commercial Internet service providers were established: UUNET, PSINET and CERFNET. Newsgroups and BITNET are important independent networks, which provide gateways to the Internet, and later merged with the Internet. Various other commercial and educational networks, such as Telenet, Tymnet, Compuserve and JANET, are interconnected with the ever-developing Internet. Telenet (later known as Sprintnet) is a large privately funded national computer network, which has been dialing Internet for free in American cities since the 1970s. With the increasing popularity of TCP/ IP protocol, this network finally interconnected with other networks in the1980s. The ability of TCP/ IP to work on almost any existing communication network makes the development very easy, although the rapid development of the Internet is mainly due to the emergence of commercial routers of Cisco Systems, Proteon and Juniper, the emergence of commercial Ethernet devices for local area networks and the wide implementation of TCP/IP on UNIX operating systems.
Common uses of the Internet
For more details on this topic, please refer to e-mail.
Before the advent of the Internet, there was the concept of sending electronic text messages between parties in a way similar to mailing letters or memos. Even today, it is important to distinguish between the Internet and internal e-mail systems. Internet e-mail may be transmitted and stored on many other networks and machines without encryption under the control of both the sender and the receiver. In the meantime, the content is likely to be read or even tampered with by a third party, if someone thinks it is important enough. A purely internal or intranet mail system is much safer. In this system, information will never leave the company or organization's network, although there will be IT personnel and other personnel in any organization, and their work may involve monitoring and occasionally accessing emails that are not addressed to their other employees.
World Wide Web
Many people use the terms Internet and World Wide Web (or just the Web) interchangeably, but, as mentioned above, these two terms are not synonyms.
The World Wide Web is a huge collection of documents, images and other resources linked by hyperlinks and URLs. These hyperlinks and URLs allow web servers and other machines that store originals and cached copies of these resources to transmit them on demand using HTTP (Hypertext Transfer Protocol). HTTP is just one of the communication protocols used on the Internet.
Web services also use HTTP to allow software systems to communicate in order to share and exchange business logic and data.
Software products that can access network resources are correctly called user agents. In normal use, web browsers such as Internet Explorer and Firefox access web pages and allow users to navigate from one web page to another through hyperlinks. Web documents can contain almost any combination of computer data, including graphics, sound, text, video, multimedia and interactive content, including games, office applications and scientific presentations.
Use search engines such as Yahoo through keyword-driven Internet research! And Google, millions of people around the world can easily and instantly access a large number of different online information. Compared with encyclopedias and traditional libraries, the World Wide Web makes information and data suddenly extremely scattered.
Using the Internet, it is also easier for individuals and organizations to publish ideas and information to a large audience than ever before. Anyone can find a way to publish a web page or build a website with little initial cost. However, it is still a difficult and expensive proposal to publish and maintain large professional websites full of attractive, diverse and up-to-date information.
Many individuals and some companies and groups use "weblogs" or blogs, which are largely used as online diaries that are easy to update. Some commercial organizations encourage employees to provide advice in their professional fields on their websites, hoping that visitors will be moved by professional knowledge and free information, and thus attracted by the company. An example of this approach is Microsoft, whose product developers publish their personal blogs to arouse public interest in their work.
Personal web pages published by large service providers are still very popular and have become more and more complex. Although websites such as Angelfire and GeoCities existed in the early days of the Internet, the updated products of websites such as Facebook and MySpace now have a large number of followers. These operations usually advertise themselves as social networking services, not just web hosts.
Advertising on popular web pages is profitable, and e-commerce or selling products and services directly through the internet is also growing.
In the early days, web pages were usually created as a set of complete and isolated HTML text files stored on a Web server. Recently, websites are increasingly created by using content management system (CMS) or wiki software, with little content at first. The contributors of these systems can be paid employees, members of clubs or other organizations or members of the public. They use the editing pages designed for this purpose to fill in the basic database, and temporary visitors can view and read these contents in the final HTML form. There may or may not be a built-in editing, approval and security system in the process of obtaining new input content and providing it to target visitors.
Social shock
Because of its wide availability and accessibility, the Internet has made it possible for new forms of social interaction, activities and organizations.
Social networking sites such as Facebook and MySpace have created a new form of social interaction. Users of these websites can add various items to their personal pages, show their common interests and connect with others. It is also possible to find a large circle of existing acquaintances, especially if a website allows users to use their real names and allows communication among existing large groups of people.
Sites like meetup.com exist to allow wider group announcements. These groups may mainly exist for face-to-face meetings, but there may be various small interactions on their group's site in meetup.org or other similar sites.
Political organization and censorship system
For more details on this topic, please refer to Internet censorship.
In a democratic society, the Internet has gained new relevance as a political tool. Howard dean's presidential campaign in 2004 was famous for its ability to raise donations through the Internet. Many political groups use the Internet to realize a brand-new organizational method to carry out Internet activism.
Some governments, such as those of Cuba, Iran, North Korea, Myanmar, People's Republic of China (PRC) and Saudi Arabia, restrict their domestic users from accessing the Internet, especially political and religious content. This is achieved through software that filters domains and content, so that they are not easy to access or obtain without careful circumvention.
In Norway, Denmark, Finland and Sweden, major Internet service providers voluntarily (probably to prevent this arrangement from becoming law) agreed to restrict access to websites listed by the police. Although this list of banned websites only contains the addresses of known child pornography websites, the contents of the list are confidential. [need to quote]
Many countries, including the United States, have enacted laws that make it illegal to possess or disseminate certain materials (such as child pornography), but no filtering software is used.
There are many free and commercially available software programs that users can choose to use to stop offensive websites on personal computers or networks, such as restricting children's exposure to pornography or violence. See content control software.
leisure activity
Since the advent of the World Wide Web, the Internet has been the main source of leisure. Interesting social experiments such as MUDs and MOOs conducted on university servers, as well as news groups related to humor, have gained most of the main traffic. Nowadays, many Internet forums have special games and funny videos. Short cartoons in the form of Flash movies are also very popular. More than 6 million people use blogs or message boards as a means to communicate and share ideas.
Pornography and gambling make full use of the World Wide Web, and often provide an important source of advertising revenue for other websites. Although many governments try to restrict the use of the Internet in these two industries, this usually cannot stop their widespread popularity.
One of the main areas of leisure on the Internet is multiplayer games. This form of leisure creates a community where people of all ages and backgrounds can enjoy the fast-paced world of multiplayer games. These games range from MMORPG to first-person shooter, from role-playing games to online gambling. This has completely changed the way many people interact and spend their free time on the Internet.
Although online games have existed since 1970' s, the modern online game mode began with services that gamers usually subscribe to, such as GameSpy and MPlayer. Non-subscribers are restricted to certain types of games or certain games.
Many people use the Internet to access and download music, movies and other works for entertainment and relaxation. As mentioned above, centralized servers and distributed peer-to-peer technologies are used, all of which have paid and unpaid sources. Caution is necessary, because some of these sources pay more attention to the rights of creators and copyright law than others.
Many people use the World Wide Web to get news, weather and sports reports, plan and book holidays, and find more information about their random ideas and temporary interests.
People use chat, text messages and emails to keep in touch with friends all over the world, sometimes just like some former pen pals. Social networking sites like MySpace, Facebook and many others also keep people in touch for fun.
There are more and more Web desktops on the Internet, and users can access their files, folders and settings through the Internet.
Network slack has become a serious consumption of company resources; A study by Peninsula Business Services shows that British employees spend an average of 57 minutes surfing the Internet every day at work. [9]
Complex building
Many computer scientists regard the Internet as "a typical example of a large-scale, highly engineered but highly complex system". [10] The Internet is extremely heterogeneous. (For example, the data transmission rate and the physical characteristics of the connection vary greatly. ) The Internet shows an "emergent phenomenon" that depends on its large-scale organization. For example, the data transmission rate shows time self-similarity. What further increases the complexity of the Internet is the ability of multiple computers to use the Internet through only one node, thus creating the possibility of a very deep and layered subnet that can be expanded indefinitely in theory (regardless of the programming limitations of the IPv4 protocol). However, since the principle of this structure can be traced back to1960s, it may not be the most suitable solution for modern needs, so the possibility of developing alternative structures is being studied. [ 1 1]
According to an article in Discovery magazine in June 2007, the total weight of all the electrons moving on the Internet in one day is 0.2 millionth of an ounce. [12] Others estimate that this is close to 2 ounces (50 grams). [ 13]
marketing
Internet has also become a big market for the company; Nowadays, some of the biggest companies have grown up by using the Internet (also known as e-commerce) for low-cost advertising and high-efficiency business. This is the fastest way to spread information to a large number of people at the same time. The internet then completely changed shopping-for example; A person can order a CD online and receive an email within a few days, or download it directly in some cases. Internet has also greatly promoted personalized marketing, which makes it easier for companies to sell products to specific people or groups than any other advertising media.
Examples of personalized marketing include online communities, such as MySpace, Friendster, Orkut, Facebook, etc. Thousands of Internet users join these communities to advertise themselves and make friends online. Many of these users are teenagers, ranging in age from 65 to 25. Conversely, when they advertise for themselves, they publicize their interests and hobbies. Online marketing companies can use these as information about what these users will buy online and promote their own products to these users.