The Internet is an international collection of computer networks` that all understand a standard system of addresses and commands, connected together through backbone systems. It was started in 1969, when the U.S. Department of Defence established a nationwide network to connect a handful of universities and contractors. The original idea was to increase computing capacity that could be shared by users in many locations and to find out what it would take for computer networks to survive a nuclear war or other disaster by providing multiple path between users. People on the ARPNET (as this nationwide network was originally called) quickly discovered that they could exchange messages and conduct electronic "conferences" with distant colleagues for purposes that had nothing to do with the military industrial complex. If somebody else had something interesting stored on their computer, it was a simple matter to obtain a copy (assuming the owner did not protect it).

　　Over the years, additional networks joined which added access to more and more computers. The first international connections, to Norway and England, were added in 1973. Today thousands of networks and millions of computers are connected to the Internet. It is growing so quickly that nobody can say exactly how many users "On the Net".

　　The Internet is the largest repository of information which can provide very very large network resources. The network resources can be divided into network facilities resources and network information resources. The network facilities resources provide us the ability of remote computation and communication. The network information resources provides us all kinds of information services, such as science, education, business, history, law, art, and entertainment, etc.

　　The goal of your use of the Internet is exchanging messages or obtaining information. What you need to know is that you can exchange message with other computers on the Internet and use your computer as a remote terminal on distant computers. But the internal details of the link are less important, as long as it works. If you connect computers together on a network, each computer must have a unique address, which could be either a word or a number. For example, the address of Sam's computer could be Sam, or a number.

　　The Internet is a huge interconnected system, but it uses just a handful of method to move data around. Until the recent explosion of public interest in the Internet, the vast majority of the computers on the Net use the Unix operating system. As a result, the standard Unix commands for certain Internet services have entered the online community's languages as both nouns and verbs to describe the services themselves. Some of the services that the Internet can provide are: Mail, Remote use of another computer (Telnet), File Transfer (FTP), News, and Live conversation.

　　The most commonly used network service is electronic mail (E-mail), or simply as mail. Mail permits network users to send textual messages to each other. Computers and networks handle delivering the mail, so that communicating mail users do not have to handle details of delivery, and do not have to be present at the same time or place.

　　The simplest way to access a file on another host is to copy it across the network to your local host. FTP can do this.

　　Presently, a user with an account on any Internet machine can establish a live connection to any other machine on the Net from the terminal in his own office or laboratory. It is only necessary to use the Unix command that sets up a remote terminal connection (Telnet), followed by the address of the distant machine.

　　Before you can use the Internet, you must choose a way to move data between the Internet and your PC. This link may be a high-speed data communication circuit, a local area network (LAN), a telephone live or a radio channel. Most likely, you will use a Modem attached to your telephone line to talk to the Internet. Naturally, the quality of your Internet connection and service, like many other things in life, is dictated by the amount of money that you are willing to spend.

　　Although all these services can well satisfy the needs of the users for information exchange, a definite requirement is needed for the users. Not only should the users know where the resources locates, but also he should know some operating commands concerned to ease the searching burden of the users, recently some convenient searching tools appears, such as Gopher, WWW and Netscape.

　　World wide web (www) is a networked hypertext protocol and user interface. It provides access to multiple services and documents like Gopher does but is more ambitious in its method. A jump to other Internet service can be triggered by a mouse click on a "hotlinked" word, image, or icon on the Web page.

　　As more and more systems join the Internet, and as more and more forms of information can be converted to digital form, the amount of stuff available to Internet users continues to grow. At some points very soon after the nationwide (and later worldwide) Internet started to grow, people began to treat the Net as a community, with its own tradition and customs. For example, somebody would ask a question in a conference, and a complete stranger would send back an answer: after the same question were repeated several time by people who hadn't seen the original answers, somebody else gathered list of  "frequently asked questions" and placed it where newcomers could find it.

　　So we can say that the Internet is your PC's window to the rest of the world.

　　Internet是由位于世界各地相互通信的计算机连接而成的巨大的计算机网络。

　　Internet是计算机网络的国际性的集合，这些网络都符合具有地址和命令的标准体系，并经骨干网连在一起。Internet始建于1969年，当时美国国防部为连接少数几所大学和协议企业而建立了一个全国性网络。最初的想法是要增加计算机能力并可由许多地点的用户共享，并且通过提供用户间多条路径来找到哪一种计算机网络能够在核战或其他灾难中幸存。ARPNET（这种全国网络最初的名称）上的用户很快就发现他们可以与远距离的同事交换消息，并且进行某种目的的电子“会议”，而这些目的与军事工业企业没有任何关系。如果另外一些人在其计算机中存有有趣的东西，得到其拷贝是很容易的事（假定拥有者没有进行保护）。

　　几年间，新的网络接入使越来越多的计算机加入进来。在1973年进行了第一次与挪威和英国的国际连接。今天，有成千上万的计算机网络和数百万台计算机与Internet相连。Internet发展如此之快以至于没有人能准确地说出网上有多少用户。

　　Internet是最大的信息宝库，它可以提供非常巨大的网络资源。这种网络资源可分为网络设备资源和网络信息资源。网络设备资源使我们能够进行远程计算和通信。网络信息资源向我们提供各种各样的信息服务，如科学、教育、商务、历史、法律、艺术和娱乐等等。

　　使用Internet的目的是交换消息或获得信息。你只须知道你可以与Internet上的其他计算机交换消息并将你的计算机用作远端计算机的远程终端，而链路的内部细节并不太重要，只要网络能工作就行。若将多台计算机连接到网络上，每台计算机须有惟一的地址，地址可以是一个字或一个数字。例如Sam的计算机地址可以是Sam或一个数字。

　　虽然Internet是一个巨大的互联系统，但它仅使用一点简单办法就将数据传来传去。近来公众对Internet产生了极大的兴趣，在这之前，绝大多数网上计算机都使用Unix操作系统。结果，用于某些Internet业务的标准Unix命令已经进入联机团体语言当作名词和动词来描述业务本身。Internet可以提供的一些服务为：电子邮件、远程使用其他计算机、文件传送、电子新闻和实况对话。

　　最常使用的网络服务是电子邮件，或简称邮件。电子邮件允许网络用户彼此传送文本消息。邮件的传递由计算机和网络处理，邮件用户不必关心传递的细节，也不必同时在场。

　　从其他主机中获得文件的最简单的方式是通过网络将其拷贝到你的计算机上。文件传送（FTP）可完成这项工作。

　　目前，用户在Internet建立账户后，就可从其办公室和实验室的终端上与网上其他计算机建立实时连接。只需使用Unix命令Telnet来建立远程终端连接，命令后跟上远端计算机的地址即可。

　　在使用Internet之前，必须使用一种方法在你的PC机和Internet之间传送数据。这种连接的链路可以是高速数据通信电路、局域网（LAN）、电话线路或无线信道。最有可能的是，你使用Modem连到电话线上与Internet对话。当然，像生活中许多其他的事物一样，与Internet连接和服务的质量是由你所花钱的数量决定的。

　　虽然所有这些服务可以很好地满足用户对信息交换的需要，但用户仍旧还需要具有一些特定的先决条件。用户不仅要知道信息资源所处的位置，而且要知道一些有关的操作命令。为了减轻用户寻找信息的负担，近来出现了一些方便的搜索工具，如Gopher，WWW和Netscape。

　　全球网（WWW）是一种网络的超文本协议和用户界面。像Gopher一样，它提供多种服务和文件接入方法，但其方法更加有前途。向Internet其他服务的跳转可在“网”页上由鼠标器点击“热链接”的字、图像或按钮来启动。

　　随着越来越多的系统加入Internet，同时随着越来越多的信息可以转变成数字形式，Internet用户所能得到的东西也在继续增加。随着国家（后来是国际）Internet的发展，很快在某些方面人们开始将互联网看作是一个社区，有自己的传统和习惯。例如某些人会在会议上提出一个问题，一个完全陌生的人会传送一个答案；由于一些人没有看到最初的答案而多次重复这一问题，这时另外一些人会搜集一系列“经常提到的问题”并将其放置在新来者能找到的地方。

　　所以我们可以说，Internet是你的PC机通向世界其他地方的窗口。