Internet的发展历史 中英文
The Beginning - ARPAnet
The Internet started as a project by the US government. The object of the project was to create a means of communications between long distance points, in the event of a nation wide emergency or, more specifically, nuclear war. The project was called ARPAnet, and it is what the Internet started as. Funded specifically for military communication, the engineers responsible for ARPANet had no idea of the possibilities of an \
By definition, an 'Internet' is four or more computers connected by a network. ARPAnet achieved its network by using a protocol called TCP/IP. The basics around this protocol was that if information sent over a network failed to get through on one route, it would find another route to work with, as well as establishing a means for one computer to \Macintosh.
By the 80's ARPAnet, just years away from becoming the more well known Internet, had 200 computers. The Defense Department, satisfied with ARPAnets results, decided to fully adopt it into service, and connected many military computers and resources into the network. ARPAnet then had 562 computers on its network. By the year 1984, it had over 1000 computers on its network.
In 1986 ARPAnet (supposedly) shut down, but only the organization shut down, and the existing networks still existed between the more than 1000 computers. It shut down due to a failied link up with NSF, who wanted to connect its 5 countywide super computers into ARPAnet.
With the funding of NSF, new high speed lines were successfully installed at line speeds of 56k (a normal modem nowadays) through telephone lines
in 1988. By that time, there were 28,174 computers on the (by then decided) Internet. In 1989 there were 80,000 computers on it. By 1989, there were 290,000.
Another network was built to support the incredible number of people joining. It was constructed in 1992. Today - The Internet
Today, the Internet has become one of the most important technological advancements in the history of humanity. Everyone wants to get 'on line' to experience the wealth of information of the Internet. Millions of people now use the Internet, and it's predicted that by the year 2003 every single person on the planet will have Internet access. The Internet has truly become a way of life in our time and era, and is evolving so quickly its hard to determine where it will go next, as computer and network technology improve every day.
HOW IT WORKS:
It's a standard thing. People using the Internet. Shopping, playing games,conversing in virtual Internet environments.
The Internet is not a 'thing' itself. The Internet cannot just \same way as the telephone system, only there is no Internet company that runs the
Internet.
The Internet is a collection of millioins of computers that are all connected to each other, or have the means to connect to each other. The Internet is just like an office network, only it has millions of computers connected to it.
The main thing about how the Internet works is communication. How does a computer in Houston know how to access data on a computer in Tokyo to view a webpage?
Internet communication, communication among computers connected to the Internet, is based on a language. This language is called TCP/IP. TCP/IP establishes a language for a computer to access and transmit data over the Internet system.
But TCP/IP assumes that there is a physical connecetion between one computer and another. This is not usually the case. There would have to be a network wire that went to every computer connected to the Internet, but that would make the Internet impossible to access.
The physical connection that is requireed is established by way of modems,phonelines, and other modem cable connections (like cable modems or DSL). Modems on computers read and transmit data over established lines,which could be phonelines or data lines. The actual hard core connections are established among computers called routers.
A router is a computer that serves as a traffic controller for information.
To explain this better, let's look at how a standard computer might view a webpage.
1. The user's computer dials into an Internet Service Provider (ISP). The ISP might in turn be connected to another ISP, or a straight connection into the Internet backbone.
2. The user launches a web browser like Netscape or Internet Explorer and types in an internet location to go to.
3. Here's where the tricky part comes in. First, the computer sends data about it's data request to a router. A router is a very high speed powerful computer running special software. The collection of routers in the world make what is called a \operates at a speed of several gigabytes per-second. Such a speed compared to a normal modem is like comparing the heat of the sun to the heat of an ice-cube.
Routers handle data that is going back and forth. A router puts small chunks of data into packages called packets, which function similarly to envelopes. So, when the request for the webpage goes through, it uses TCP/IP protocols to tell the router what to do with the data, where it's going, and overall where the user wants to go.
4. The router sends these packets to other routers, eventually leading to the target computer. It's like whisper down the lane (only the information remains intact).
5. When the information reaches the target web server, the webserver then begins to send the web page back. A webserver is the computer where the webpage is stored that is running a program that handles requests for the webpage and sends the webpage to whoever wants to see it.
6. The webpage is put in packets, sent through routers, and arrive at the users computer where the user can view the webpage once it is assembled.
The packets which contain the data also contain special information that lets routers and other computers know how to reassemble the data in the right order.
With millions of web pages, and millions of users, using the Internet is not always easy for a beginning user, especially for someone who is not entirely comfortale with using computers. Below you can find tips tricks and help on how to use main services of the Internet.
Before you access webpages, you must have a web browser to actually be able to view the webpages. Most Internet Access Providers provide you with a web browser in the software they usually give to customers; you. The fact that you are viewing this page means that you have a web browser. The top two use browsers are Netscape
Communicator and Microsoft Internet Explorer. Netscape can be found at
netscape and MSIE can be found at microsoft /ie.
The fact that you're reading this right now means that you have a web browser. Next you must be familiar with actually using webpages. A webpage is a collection of hyperlinks, images, text, forms, menus, and multimedia. To \webpage, simply click the links it provides or follow it's own instructions (like if it has a form you need to use, it will probably instruct you how to use it). Basically, everything about a webpage is made to be self- explanetory. That is the nature of a webpage, to be easily navigatable.
\web-users.
Sometimes websites have errors. But an error on a website is not the user's fault, of course.
A 404 error means that the page you tried to go to does not exist. This could be because the site is still being constructed and the page hasn't been created yet, or because the site author made a typo in the page. There's nothing much to do about a 404 error except for e-mailing the site administrator (of the page you wanted to go to) an telling him/her about the error.
A Javascript error is the result of a programming error in the Javascript code of a website. Not all websites utilize Javascript, but many do. Javascript is different from Java, and most browsers now support Javascript. If you are using an old version of a web browser (Netscape 3.0 for example), you might get Javascript errors because sites utilize Javascript versions that your browser does not support. So, you can try getting a newer version of your web browser.
E-mail stands for Electronic Mail, and that's what it is. E-mail enables people to send letters, and even files and pictures to each other.
To use e-mail, you must have an e-mail client, which is just like a personal post office, since it retrieves and stores e-mail.
Secondly, you must have an e-mail account. Most Internet Service Providers provide free e-mail account(s) for free. Some services offer free e-mail, like Hotmail, and Geocities.
After configuring your e-mail client with your POP3 and SMTP server address (your e-mail provider will give you that information), you are ready to receive mail.
Internet的发展历史 中英文
