計(jì)算機(jī)外文翻譯

1、<p>　　畢業(yè)設(shè)計(jì)(論文)外文資料翻譯</p><p>　　專 業(yè)： 計(jì)算機(jī)科學(xué)與技術(shù) </p><p>　　姓 名： 周喜民 </p><p>　　學(xué) 號(hào)： 06120132 </p><p>　

2、　外文出處： The History of the Internet </p><p>　　附 件： 1.外文資料翻譯譯文；2.外文原文。</p><p>　　附件1：外文資料翻譯譯文</p><p>　　Internet的歷史</p><p>　　起源——ARPAnet</p><p>　　Inte

3、rnet是被美國(guó)政府作為一項(xiàng)工程進(jìn)行開(kāi)發(fā)的。這項(xiàng)工程的目的，是為了建立遠(yuǎn)距離之間點(diǎn)與點(diǎn)的通信，以便處理國(guó)家軍事范圍內(nèi)的緊急事件，例如核戰(zhàn)爭(zhēng)。這項(xiàng)工程被命名為ARPAnet，它就是Internet的前身。建立此工程的主要應(yīng)用對(duì)象就是軍事通訊，那些負(fù)責(zé)ARPAnet的工程師們當(dāng)時(shí)也沒(méi)有想到它將成為“Internet”。</p><p>　　根據(jù)定義，一個(gè)“Internet”應(yīng)該由四或者更多的計(jì)算機(jī)連接起來(lái)的網(wǎng)絡(luò)。&l

4、t;/p><p>　　ARPAnet是通過(guò)一種叫TCP/IP的協(xié)議實(shí)現(xiàn)連網(wǎng)工作的。此協(xié)議最基礎(chǔ)的工作原理是：如果信息在網(wǎng)絡(luò)中的一條路徑發(fā)送失敗，那么它將找到其他路徑進(jìn)行發(fā)送，就好象建立一種語(yǔ)言以便一臺(tái)計(jì)算機(jī)與其他計(jì)算機(jī)“交談”一樣，但不注意它是PC，或是Macintosh。</p><p>　　到了20世紀(jì)80年代，ARPAnet已經(jīng)開(kāi)始變成目前更為有名的Internet了，它擁有200臺(tái)在線

5、主機(jī)。國(guó)防部很滿意ARPAnets的成果，于是決定全力將它培養(yǎng)為能夠聯(lián)系很多軍事主機(jī)，資源共享的服務(wù)網(wǎng)絡(luò)。到了1984年，它就已經(jīng)超過(guò)1000臺(tái)主機(jī)在線了。</p><p>　　在1986年ARPAnet關(guān)閉了，但僅僅是建立它的機(jī)構(gòu)關(guān)閉了，而網(wǎng)絡(luò)繼續(xù)存在與超過(guò)1000臺(tái)的主機(jī)之間。由于使用NSF連接失敗，ARPAnet才被關(guān)閉。NSF是將5個(gè)國(guó)家范圍內(nèi)的超級(jí)計(jì)算機(jī)連入ARPAnet。</p><

6、;p>　　隨著NSF的建立，新的高速的傳輸介質(zhì)被成功的使用，在1988年，用戶能通過(guò)56k的電話線上網(wǎng)。在那個(gè)時(shí)候有28，174臺(tái)主機(jī)連入Internet。到了1989年有80，000臺(tái)主機(jī)連入Internet。到1989年末，就有290，000臺(tái)主機(jī)連入了。</p><p>　　另外還有其他網(wǎng)絡(luò)被建立，并支持用戶以驚人的數(shù)量接入。于1992年正式建立。</p><p>　　現(xiàn)狀——

7、Internet</p><p>　　如今，Internet已經(jīng)成為人類歷史上最先進(jìn)技術(shù)的一種。每個(gè)人都想“上網(wǎng)”去體驗(yàn)一下Internet中的信息財(cái)富。成千上百的人都用Internet。預(yù)計(jì)，到了2003年世界上的每個(gè)人，都將擁有Internet接入。Internet已經(jīng)真正成為我們這個(gè)年代生活的一部分。由于計(jì)算機(jī)技術(shù)和網(wǎng)絡(luò)技術(shù)每天都在改變，我們很難想象Internet下一步將發(fā)展成什么樣子。</p>

8、;<p><b>　　工作原理：</b></p><p>　　現(xiàn)在，人們用Internet是一件很平常的事。他們通過(guò)Internet進(jìn)行購(gòu)物、玩游戲、聊天等娛樂(lè)活動(dòng)。</p><p>　　Internet不僅僅是一件事物。Internet也會(huì)崩潰。它的工作原理如同電話通信系統(tǒng)，只不過(guò)沒(méi)有專門(mén)的Internet公司來(lái)經(jīng)營(yíng)Internet。</p>

9、;<p>　　Internet是成千上萬(wàn)臺(tái)計(jì)算機(jī)互相連接的集合。Internet就像是辦公網(wǎng)絡(luò)一樣，不同的是，它有成千上萬(wàn)臺(tái)計(jì)算機(jī)相連接。</p><p>　　其中最主要的是Internet是如何進(jìn)行通信的。位于Houston的一臺(tái)計(jì)算機(jī)是如何通過(guò)瀏覽網(wǎng)頁(yè)而能與位于Tokyo的計(jì)算機(jī)進(jìn)行數(shù)據(jù)通信的呢？</p><p>　　Internet信息，擁有信息的計(jì)算機(jī)連接到Inter

10、net，是基于語(yǔ)言。這種語(yǔ)言叫做TCP/IP。TCP/IP建立了一種語(yǔ)言，能使計(jì)算機(jī)在Internet系統(tǒng)中傳送數(shù)據(jù)。</p><p>　　但是TCP/IP的取得也必須具備兩臺(tái)電腦之間的物理連接。當(dāng)然也未必都是這樣。但也必須存在一根網(wǎng)絡(luò)線將主機(jī)與Internet連接起來(lái)，但做到這樣，還是不可能與Internet連接的。</p><p>　　物理連接要求通過(guò)MODEM，電話線和其他類似MOD

11、EM的連接（如DSL）來(lái)建立。計(jì)算機(jī)上的MODEM通過(guò)已建立的通信線進(jìn)行收發(fā)數(shù)據(jù)，通信線可以是電話線或是數(shù)據(jù)線。事實(shí)上計(jì)算機(jī)之間建立連接的硬核被成為路由器。</p><p>　　路由器就是計(jì)算機(jī)中進(jìn)行信息交互的管理器。</p><p>　　為了更好的對(duì)它說(shuō)明，讓我們來(lái)看看一臺(tái)標(biāo)準(zhǔn)的計(jì)算機(jī)是怎樣瀏覽網(wǎng)頁(yè)的？</p><p>　　1、用戶計(jì)算機(jī)撥號(hào)進(jìn)入ISP。而此ISP

12、可能還要連接入其他ISP，或是直接進(jìn)入Internet主干。</p><p>　　2、用戶打開(kāi)網(wǎng)頁(yè)瀏覽器如NETSCAPE或是IE。</p><p>　　3、接下來(lái)是進(jìn)入Internet的棘手部分。首先，用戶計(jì)算機(jī)相路由器發(fā)出請(qǐng)求。路由器是一種高速高效的計(jì)算機(jī)運(yùn)行的專門(mén)軟件。世界上所有路由的連接便形成了Internet的主干，在這里傳送Internet上的所有數(shù)據(jù)。目前主干網(wǎng)上的處理速度為

13、每秒幾千兆字節(jié)。這樣的速度分配到一只MODEM上，就好比太陽(yáng)光的熱量分配到一塊冰上的熱量一樣。</p><p>　　4、路由器發(fā)送或接受數(shù)據(jù)。它將一小段數(shù)據(jù)分別打包，形成數(shù)據(jù)報(bào)，就像包裹一樣。因此，當(dāng)請(qǐng)求網(wǎng)頁(yè)瀏覽是，就用TCP/IP協(xié)議告訴路由器如何處理這些數(shù)據(jù)，將這些數(shù)據(jù)發(fā)送去哪里，用戶主要想去哪里。</p><p>　　5、路由器將這些數(shù)據(jù)報(bào)發(fā)送給其他的路由器，最終轉(zhuǎn)到目標(biāo)主機(jī)上。就像

14、傳耳語(yǔ)的游戲一樣（當(dāng)然，只有完整的信息才能被傳送）。</p><p>　　6、當(dāng)信息到達(dá)目標(biāo)網(wǎng)頁(yè)的服務(wù)器是，服務(wù)器就開(kāi)始將網(wǎng)頁(yè)信息發(fā)送回去。一臺(tái)網(wǎng)頁(yè)服務(wù)器，就是網(wǎng)頁(yè)存儲(chǔ)所在的計(jì)算機(jī)，它能對(duì)網(wǎng)頁(yè)進(jìn)行編輯，并將它發(fā)送給用戶。網(wǎng)頁(yè)被分成數(shù)據(jù)報(bào)，通過(guò)路由器，最終到達(dá)用戶計(jì)算機(jī)，這樣，用戶就能瀏覽網(wǎng)頁(yè)了。數(shù)據(jù)報(bào)中含有相關(guān)的數(shù)據(jù)以及一些必須的信息讓路由器或其他計(jì)算機(jī)知道如何將數(shù)據(jù)報(bào)按正確的順序重新組裝成原始的數(shù)據(jù)段。<

15、/p><p>　　有了成千上萬(wàn)的網(wǎng)頁(yè)和成千上萬(wàn)的用戶，對(duì)于初學(xué)者來(lái)說(shuō)使用Internet將不再那么容易，尤其是那些不太精通電腦的人。接下來(lái)，你將能找到一些上網(wǎng)的小技巧和使用Internet主要服務(wù)的幫助。</p><p>　　在你打開(kāi)網(wǎng)頁(yè)之前，你必須有一個(gè)網(wǎng)頁(yè)瀏覽器用于瀏覽網(wǎng)頁(yè)。大部分網(wǎng)絡(luò)服務(wù)商都會(huì)給用戶提供一個(gè)網(wǎng)絡(luò)瀏覽器。當(dāng)你在瀏覽網(wǎng)頁(yè)時(shí)，其實(shí)就是在使用瀏覽器。目前使用最廣泛的網(wǎng)頁(yè)瀏覽器是N

16、etscape和MSIE。Netscape能自動(dòng)連接到www.netscape.com，MSIE能自動(dòng)連接www.microsoft.com。</p><p>　　接下來(lái)你就必須熟悉如何使用網(wǎng)頁(yè)。網(wǎng)頁(yè)是超鏈接、圖片、文本、表格、按鈕以及多媒體的集合。只需點(diǎn)擊網(wǎng)頁(yè)提供的連接或是按照網(wǎng)頁(yè)的步驟（比如，如果你需要用網(wǎng)頁(yè)中的一張表，旁邊就會(huì)有使用這張表的幫助）做，你就可以進(jìn)行網(wǎng)上沖浪了?；旧希W(wǎng)頁(yè)中的每個(gè)元素都可以自我

17、移植。</p><p>　　“哦，不！又是404出錯(cuò)！‘不能找到相關(guān)網(wǎng)頁(yè)’”這是上網(wǎng)初學(xué)者中很普通的言論。</p><p>　　有時(shí)網(wǎng)站也會(huì)出錯(cuò)。當(dāng)然網(wǎng)站的錯(cuò)誤跟用戶的操作沒(méi)有關(guān)系。</p><p>　　404出錯(cuò)意思是你想找的那個(gè)網(wǎng)頁(yè)不存在。這有可能是因?yàn)榫W(wǎng)站仍在建設(shè)中，頁(yè)面還沒(méi)有被創(chuàng)建，或者是因?yàn)榫W(wǎng)站的制作者正在對(duì)頁(yè)面進(jìn)行修改。當(dāng)出現(xiàn)404出錯(cuò)時(shí)，除了對(duì)網(wǎng)站管理

18、發(fā)電子郵件，告訴他/她關(guān)于出錯(cuò)的問(wèn)題，就別無(wú)他法了。</p><p>　　Javascript出錯(cuò)是由于網(wǎng)站中的Javascript的程序代碼出錯(cuò)造成的。并非所有的網(wǎng)頁(yè)都使用Javascript，但有很多是用Javascript的。Javascript不同于JAVA，目前大部分瀏覽器都支持Javascript。如果你現(xiàn)在用的是舊版的網(wǎng)頁(yè)瀏覽器，那么就有可能出現(xiàn)Javascript出錯(cuò)，那是因?yàn)槟愕臑g覽器的版本低于

19、站點(diǎn)使用的Javascript版本。所以，你應(yīng)該為你的瀏覽器升級(jí)到新的版本。</p><p>　　電子郵件即電子方式的郵件。電子郵件能使人們互相收發(fā)信件，甚至是文件和圖片。</p><p>　　要使用電子郵件，那你就必須擁有一個(gè)電子郵件客戶端，它就像是郵遞員，為你收發(fā)電子郵件。</p><p>　　其次，你必須有一個(gè)電子郵件帳戶。大部分網(wǎng)絡(luò)服務(wù)供應(yīng)商都會(huì)提供給用戶一

20、個(gè)免費(fèi)的電子郵件帳戶。有的網(wǎng)站也提供免費(fèi)的電子郵箱，如Hotmail和Geocities。</p><p>　　配置好電子郵件客戶端，包括POP3和SMTP服務(wù)器地址（電子郵件供應(yīng)商會(huì)給你相關(guān)信息）之后，你就可以準(zhǔn)備收郵件了。</p><p>　　附件是與信一起發(fā)過(guò)來(lái)的文件，如果有人發(fā)給你帶有附件的郵件，但你不知道他是誰(shuí)，就不要打開(kāi)那個(gè)附件。它有可能是病毒或是其他惡意的程序。用戶不會(huì)通過(guò)閱

21、讀郵件而被傳染病毒，你不得不運(yùn)行殺毒軟件來(lái)防止病毒感染。</p><p>　　簽名是很多電子郵件程序的一個(gè)特征。簽名加在郵件的末尾。你可以將生動(dòng)的文本，你職業(yè)信息或是其他你喜歡的東西作為簽名。</p><p>　　設(shè)想在國(guó)際互聯(lián)網(wǎng)中的電腦就像海中的島嶼。那么海洋中就充滿了數(shù)百萬(wàn)的島嶼。這就是國(guó)際互聯(lián)網(wǎng)。設(shè)想島與島之間是通過(guò)發(fā)送和接收船只來(lái)聯(lián)絡(luò)的。那么島嶼就有接收和發(fā)送船只的港口。</

22、p><p>　　在國(guó)際互聯(lián)網(wǎng)中的電腦有被叫做“港口”的端口。端口只是一個(gè)象征性的對(duì)象，它使得電腦能在網(wǎng)絡(luò)（或是國(guó)際互聯(lián)網(wǎng)）上運(yùn)轉(zhuǎn)。這種方法與上面提到的“島嶼、海洋”形象論類似。</p><p>　　遠(yuǎn)程登陸涉及到在服務(wù)器上直接用文本連接來(lái)使用端口。</p><p>　　幾乎每種互聯(lián)網(wǎng)活動(dòng)，如訪問(wèn)網(wǎng)頁(yè)、聊天、以及發(fā)電子郵件都是依托遠(yuǎn)程登陸來(lái)實(shí)現(xiàn)的。</p>

23、<p>　　遠(yuǎn)程登陸需要一個(gè)遠(yuǎn)程登陸客戶服務(wù)器。遠(yuǎn)程登陸程序兼容于Windows系統(tǒng)，所以Windows用戶可以通過(guò)在對(duì)話窗口鍵入telnet（不加's）來(lái)接入遠(yuǎn)程登陸軟件。Linux系統(tǒng)則將它創(chuàng)建在命令行里：鍵入telnet。用于Macintosh的普通遠(yuǎn)程登陸程序是NCSA遠(yuǎn)程登陸軟件。 </p><p>　　任何一個(gè)服務(wù)軟件（網(wǎng)頁(yè)端口監(jiān)督程序，聊天端口監(jiān)督程序）都可以通過(guò)遠(yuǎn)程登陸被接入，即

24、使這些軟件不經(jīng)常以這種方法被接入。</p><p>　　舉例來(lái)說(shuō)，直接與郵件服務(wù)器連接并通過(guò)與郵件服務(wù)軟件交流來(lái)校對(duì)你的郵件是可能的，但用電子郵件客戶服務(wù)器卻更簡(jiǎn)單（當(dāng)然如此）。</p><p>　　世界各地有數(shù)百萬(wàn)的網(wǎng)頁(yè)，那么你如何知道哪個(gè)網(wǎng)頁(yè)的地址是你需要的呢？</p><p>　　搜索工具能節(jié)約時(shí)間。搜索工具是一個(gè)非常龐大的網(wǎng)站，它使你能夠搜尋它自有的網(wǎng)站數(shù)據(jù)

25、庫(kù)。</p><p>　　舉例來(lái)說(shuō)，如果你要找關(guān)于“狗”的網(wǎng)站，你可以搜索“狗”或“狗的信息”。這里有一些搜索引擎：</p><p>　　1. Altavista (http://www.altavista.digital.com) - Web spider & Indexed</p><p>　　2. Yahoo (http://www.yahoo.com

26、) - Web spider & Indexed Collection</p><p>　　3. Excite (http://www.excite.com) - Web spider & Indexed</p><p>　　4. Lycos (http://www.lycos.com) - Web spider & Indexed</p><p

27、>　　5. Metasearch (http://www.metasearch.com) - Multiple search</p><p>　　網(wǎng)絡(luò)蜘蛛是一種搜索引擎使用的程序，它隨著可能找到的任何鏈接從一個(gè)網(wǎng)頁(yè)到另一個(gè)網(wǎng)頁(yè)。</p><p>　　這意味著只要它自己的時(shí)間和速度允許，搜索引擎就能盡可能多地在網(wǎng)絡(luò)上逐字搜尋信息。編入索引的收集使用手動(dòng)附加鏈接。比如雅虎網(wǎng)站。你可以點(diǎn)擊

28、“電腦和網(wǎng)絡(luò)”，再點(diǎn)擊“硬件”，然后點(diǎn)擊“貓”（調(diào)制解調(diào)器）等等。那么通過(guò)分類的過(guò)程，與你要的類別相關(guān)的網(wǎng)站就找到了。</p><p>　　Metasearch 同時(shí)搜索許多搜索引擎，從十個(gè)引擎中找出最上面的搜索結(jié)果，使得搜索變得有效很多。一旦你能夠使用搜索引擎，你就能有效的找到你要的網(wǎng)頁(yè)。伴隨著網(wǎng)絡(luò)系統(tǒng)和多用戶系統(tǒng)時(shí)代的來(lái)臨，安全總是系統(tǒng)開(kāi)發(fā)和系統(tǒng)操作人員考慮的問(wèn)題。</p><p>　

29、　從美國(guó)電報(bào)電話公司和它的電話網(wǎng)組建開(kāi)始，黑客已為許多人所知。黑客就是一直尋找途徑侵入系統(tǒng)的人。這過(guò)去不是一個(gè)大問(wèn)題，因?yàn)榫W(wǎng)絡(luò)系統(tǒng)對(duì)于那些能夠提供必要的電腦安全措施的大型法人公司和政府的電腦來(lái)說(shuō)是有限的。</p><p>　　現(xiàn)今最大的問(wèn)題是個(gè)人信息。為什么當(dāng)你通過(guò)網(wǎng)絡(luò)購(gòu)物時(shí)應(yīng)該小心？讓我們快速地看一看國(guó)際互聯(lián)網(wǎng)時(shí)如何工作的。用戶將信用卡的信息傳遞到網(wǎng)頁(yè)上。看起來(lái)安全，對(duì)嗎？其實(shí)未必。當(dāng)用戶提交信息時(shí)，它就會(huì)流過(guò)

30、組成互聯(lián)網(wǎng)主干網(wǎng)的一系列的電腦。信息是小塊的一包包的，被稱作信息包。</p><p>　　這里有個(gè)問(wèn)題：當(dāng)信息通過(guò)這巨大的支柱被傳遞時(shí)，怎樣防止黑客在支柱的某一點(diǎn)上攔截?cái)?shù)據(jù)流？你接入網(wǎng)站時(shí)哥哥不會(huì)看著你，但用戶在傳遞私人信息時(shí)應(yīng)該清楚潛在的威脅。</p><p>　　加強(qiáng)安全有很多方法，如密碼保護(hù)，一種最重要的措施：加密。加密指將數(shù)據(jù)攪亂成只能在另一終端才能譯出的密碼。像Netscape

31、Communicator和Internet Explore這樣的瀏覽器為在線傳遞提供了特色的加密支持。</p><p>　　一些加密措施比其他工作地更好。最先進(jìn)的加密系統(tǒng)被稱作DES（數(shù)據(jù)加密準(zhǔn)則），且它被美國(guó)安全局采納，因?yàn)樗徽J(rèn)為是如此難以非法侵入以至他們認(rèn)為如果它落入其它國(guó)家手中會(huì)有安全風(fēng)險(xiǎn)。</p><p>　　DES用單獨(dú)的信息鑰匙來(lái)開(kāi)啟一整個(gè)文件。問(wèn)題是有75萬(wàn)億可能的鑰匙可用

32、，所以它是一個(gè)很難破壞的系統(tǒng)。一個(gè)文件被侵入并被解碼，但這是一個(gè)需14000臺(tái)電腦進(jìn)入互聯(lián)網(wǎng)系統(tǒng)的綜合的努力過(guò)程，并需要花一段時(shí)間來(lái)做。所以大部分黑客沒(méi)有那么多的資源。</p><p><b>　　附件2：外文原文</b></p><p>　　The History of the Internet</p><p>　　The Beginning

33、 - ARPAnet</p><p>　　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 emerg

34、ency 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 po

35、ssibilities of an "Internet." </p><p>　　By definition, an 'Internet' is four or more computers connected by a network. </p><p>　　ARPAnet achieved its network by using a protoco

36、l 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

37、to "talk" to another computer, regardless of whether it was a PC or a Macintosh. </p><p>　　By the 80's ARPAnet, just years away from becoming the more well known Internet, had 200 computers. Th

38、e 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 y

39、ear 1984, it had over 1000 computers on its network. </p><p>　　In 1986 ARPAnet (supposedly) shut down, but only the organization shut</p><p>　　down, and the existing networks still existed betwe

40、en the more than 1000</p><p>　　computers. It shut down due to a failied link up with NSF, who wanted to</p><p>　　connect its 5 countywide super computers into ARPAnet. </p><p>　　Wit

41、h the funding of NSF, new high speed lines were successfully installed</p><p>　　at line speeds of 56k (a normal modem nowadays) through telephone lines</p><p>　　in 1988. By that time, there were

42、 28,174 computers on the (by then decided) Internet. In 1989 there were 80,000 computers on it. By 1989, there were 290,000. </p><p>　　Another network was built to support the incredible number of people<

43、/p><p>　　joining. It was constructed in 1992. </p><p>　　Today - The Internet</p><p>　　Today, the Internet has become one of the most important technological advancements in the history

44、 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

45、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 net</p><p>　　HOW

46、 IT WORKS:</p><p>　　It's a standard thing. People using the Internet. Shopping, playing games,conversing in virtual Internet environments. </p><p>　　The Internet is not a 'thing' its

47、elf. The Internet cannot just "crash." It functions the same way as the telephone system, only there is no Internet company that runs the Internet. </p><p>　　The Internet is a collection of millioi

48、ns 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. </p><p>　　The

49、 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? </p><p>　　Internet communication, communication amo

50、ng 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. </p><p>　　Bu

51、t 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

52、would make the Internet impossible to access. </p><p>　　The physical connection that is requireed is established by way of modems,phonelines, and other modem cable connections (like cable modems or DSL). Mod

53、ems 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. </p><p>　　A router is

54、a computer that serves as a traffic controller for information. </p><p>　　To explain this better, let's look at how a standard computer might view a webpage. </p><p>　　1. The user's comp

55、uter 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. </p><p>　　2. The user launches a web browser like N

56、etscape or Internet Explorer and types in an internet location to go to. </p><p>　　3. Here's where the tricky part comes in. First, the computer sends data about it's data request to a router. A rout

57、er is a very high speed powerful computer running special software. The collection of routers in the world make what is called a "backbone," on which all the data on the Internet is transferred. The backbone pr

58、esently 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. </p><p>　　Routers handle data that is go

59、ing 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 w

60、hat to do with the data, where it's going, and overall where the user wants to go. </p><p>　　4. The router sends these packets to other routers, eventually leading to the target computer. It's like w

61、hisper down the lane (only the information remains intact). </p><p>　　5. When the information reaches the target web server, the webserver then begins to send the web page back. A webserver is the computer w

62、here 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. </p><p>　　6. The webpage is put in packets, sent through routers,

63、and arrive at the users computer where the user can view the webpage once it is assembled. </p><p>　　The packets which contain the data also contain special information that lets routers and other computers

64、know how to reassemble the data in the right order. </p><p>　　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

65、entirely comfortale with using computers. Below you can find tips tricks and help on how to use main services of the Internet. </p><p>　　Before you access webpages, you must have a web browser to actually be

66、 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. Th

67、e top two use browsers are Netscape Communicator and Microsoft Internet Explorer. Netscape can be found at www.netscape.com and MSIE can be found at www.microsoft.com/ie. </p><p>　　The fact that you're r

68、eading this right now means that you have a web browser. </p><p>　　Next you must be familiar with actually using webpages. A webpage is a collection of hyperlinks, images, text, forms, menus, and multimedia.

69、 To "navigate" a 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

70、 a webpage is made to be self- explanetory. That is the nature of a webpage, to be easily navigatable. </p><p>　　"Oh no! a 404 error! 'Cannot find web page?'" is a common remark made by new

71、 web-users. </p><p>　　Sometimes websites have errors. But an error on a website is not the user's fault, of course.</p><p>　　A 404 error means that the page you tried to go to does not exist

72、. 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-mail

73、ing the site administrator (of the page you wanted to go to) an telling him/her about the error.</p><p>　　A Javascript error is the result of a programming error in the Javascript code of a website. Not all

74、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

75、 errors because sites utilize Javascript versions that your browser does not support. So, you can try getting a newer version of your web browser. </p><p>　　E-mail stands for Electronic Mail, and that's

76、what it is. E-mail enables people to send letters, and even files and pictures to each other. </p><p>　　To use e-mail, you must have an e-mail client, which is just like a personal post office, since it retr

77、ieves and stores e-mail. </p><p>　　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 Geoci

78、ties. </p><p>　　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. </p><p>　　An att

79、achment is a file sent in a letter. If someone sends you an attachment and you don't know who it is, don't run the file, ever. It could be a virus or some other kind of nasty programs. You can't get a virus j

80、ust by reading e-mail, you'll have to physically execute some form of program for a virus to strike. </p><p>　　A signature is a feature of many e-mail programs. A signature is added to the end of every e

81、-mail you send out. You can put a text graphic, your business information, anything you want. </p><p>　　Imagine that a computer on the Internet is an island in the sea. The sea is filled with millions of isl

82、ands. This is the Internet. Imagine an island communicates with other island by sending ships to other islands and receiving ships. The island has ports to accept and send out ships. </p><p>　　A computer on

83、the Internet has access nodes called ports. A port is just a symbolic object that allows the computer to operate on a network (or the Internet). This method is similar to the island/ocean symbolism above. </p><

84、;p>　　Telnet refers to accessing ports on a server directly with a text connection. Almost every kind of Internet function, like accessing web pages,"chatting," and e-mailing is done over a Telnet connection.

85、 </p><p>　　Telnetting requires a Telnet client. A telnet program comes with the Windows system, so Windows users can access telnet by typing in "telnet" (without the "'s) in the run dialog

86、. Linux has it built into the command line; telnet. A popular telnet program for Macintosh is NCSA telnet. </p><p>　　Any server software (web page daemon, chat daemon) can be accessed via telnet, although th

87、ey are not usually meant to be accessed in such a manner. For instance, it is possible to connect directly to a mail server and check your mail by interfacing with the e-mail server software, but it's easier to use a

88、n e-mail client (of course). </p><p>　　There are millions of WebPages that come from all over the world, yet how will you know what the address of a page you want is? </p><p>　　Search engines sa

89、ve the day. A search engine is a very large website that allows you to search it's own database of websites. For instance, if you wanted to find a website on dogs, you'd search for "dog" or "dogs&q

90、uot; or "dog information." Here are a few search-engines. </p><p>　　1. Altavista (http://www.altavista.digital.com) - Web spider & Indexed</p><p>　　2. Yahoo (http://www.yahoo.com)

91、- Web spider & Indexed Collection</p><p>　　3. Excite (http://www.excite.com) - Web spider & Indexed</p><p>　　4. Lycos (http://www.lycos.com) - Web spider & Indexed</p><p&g

92、t;　　5. Metasearch (http://www.metasearch.com) - Multiple search</p><p>　　A web spider is a program used by search engines that goes from page to page, following any link it can possibly find. This means that

93、 a search engine can literally map out as much of the Internet as it's own time and speed allows for.</p><p>　　An indexed collection uses hand-added links. For instance, on Yahoo's site. You can clic

94、k on Computers & the Internet. Then you can click on Hardware. Then you can click on Modems, etc., and along the way through sections, there are sites available which relate to what section you're in. </p>

95、<p>　　Metasearch searches many search engines at the same time, finding the top choices from about 10 search engines, making searching a lot more effective.</p><p>　　Once you are able to use search eng

96、ines, you can effectively find the pages you want. </p><p>　　With the arrival of networking and multi user systems, security has always been on the mind of system developers and system operators. Since the d

97、awn of AT&T and its phone network, hackers have been known by many, hackers who find ways all the time of breaking into systems. It used to not be that big of a problem, since networking was limited to big corporate

98、companies or government computers who could afford the necessary computer security. </p><p>　　The biggest problem now-a-days is personal information. Why should you be careful while making purchases via a we

99、bsite? Let's look at how the internet works, quickly. </p><p>　　The user is transferring credit card information to a webpage. Looks safe, right? Not necessarily. As the user submits the information, it

100、is being streamed through a series of computers that make up the Internet backbone. The information is in little chunks, in packages called packets. Here's the problem: While the information is being transferred thro

101、ugh this big backbone, what is preventing a "hacker" from intercepting this data stream at one of the backbone points? </p><p>　　Big-brother is not watching you if you access a web site, but users

102、should be aware of potential threats while transmitting private information. There are methods of enforcing security, like password protection, an most importantly, encryption.</p><p>　　Encryption means scra

103、mbling data into a code that can only be unscrambled on the "other end." Browser's like Netscape Communicator and Internet Explorer feature encryption support for making on-line transfers. Some encryptions

104、work better than others. The most advanced encryption system is called DES (Data Encryption Standard), and it was adopted by the US Defense Department because it was deemed so difficult to 'crack' that they consi