What is WORLD-WIDE WEB?
World-Wide Web (also called WWW or W3) is a hypertext-based information system. Any word in a hypertext document can be specified as a pointer to a different hypertext document where more information pertaining to that word can be found. The reader can open the second document by selecting the word (using different methods depending on the interface; in a mouse based system, a user would probably place the mouse over the word and click the mouse button); only the part of the linked document which contains relevant information will be displayed.
The second document may itself contain links to further documents.So The reader need not know where the referenced documents are, because they will be obtained and presented as they are needed.
World-Wide Web uses hypertext over the Internet:Also the linked documents may be located at different Internet sites. WWW can handle different text formats and different methods of organizing information.
The World-Wide Web also provides access to many of the other tools described in this guide, and also is becoming widely used as the major means of access to Internet resources.
Special index documents
have been created in the WWW information space and these can be searched for given keyword(s). The result is a new document which contains links to documents selected from the index.
If you were reading this document on a hypertext system, instead of this all too short explanation about hypertext, you would have a selectable pointer to a complete hypertext information web with examples and more pointers to other definitions. For instance, in the first document you might read:
The WorldWideWeb (W3) is the universe of network-accessible information, an embodiment of human knowledge. It is an initiative started at “CERN”, now with many participants. It has a body of software, and a set of protocols and conventions. W3 uses “hypertext” and multimedia techniques to make the web easy for anyone to roam browse, and contribute to.
Selecting hypertext would display the following explanation for you:
WHAT IS HYPERTEXT?
Hypertext is text which is not constrained to be linear. Hypertext is text which contains “links” to other texts. The term was coined by “Ted Nelson” around 1965 (see “History”).
HyperMedia is a term used for hypertext which is not constrained to be text: it can include graphics, video and “sound”, for example. Apparently Ted Nelson was the first to use this term too.
Then you could learn more about links and Ted Nelson. The links in WWW are not confined to text only, so the term hypermedia is more accurate – for example, the link to Ted Nelson might point to a file containing a picture of Ted Nelson. The picture would be displayed on your screen, if your computer had a suitable screen and an image viewer.
Who can use WORLD-WIDE WEB?
You must be on the international TCP/IP network (the Internet) in order to use a client on your computer to access WWW. If you are on the Internet, but don’t have a WWW client on your computer, you can still enter the World-Wide Web because several sites offer public interactive access to WWW clients (see the Remote clients section under How to get to World-Wide Web below).
If you have e-mail access only, or if you are not on the Internet, then you can not fully exploit the vast potential of WWW. However, a mail-robot is available at the address: listserv@info.cern.ch which gives e-mail access to WWW-accessible files. (see E-mail access section under How to get to World-Wide Web below).
How to get to WORLD-WIDE WEB
Users access the World-Wide Web facilities via a client called a browser, which provides transparent access to the WWW servers. If a local WWW client is not available on your computer, you may use a client at a remote site: this can be an easy way to start using WWW.
Local clients
Use of a local client is encouraged since it will provide better performance and better response time than a remote client.
Public domain clients for accessing WWW servers are available for: Macintosh, MS-DOS, VMS, VM/CMS, MVS, NeXT, Unix, X-Windows. All these platforms support a simple line mode browser. In addition, graphical clients are available for: Macintosh, Windows, X-Windows, NeXT and Unix. See the list of freely available client software in Appendix A.
To access a remote WWW client, telnet to the client site. So If you are new to WWW, you should telnet to info.cern.ch. No login is needed for this, and you will immediately enter the WWW line mode browser.
Some publicly accessible clients have been locally developed. Most remote clients are at sites with WWW servers holding information on specific areas. Telnet to the client site, and at the login: prompt enter www; no password is needed. The following remote client sites are available:
+------------------------------------------------------------------+ | | | Site Country Server Specialization | | | +------------------------------------------------------------------+ | info.funet.fi Finland | | www.huji.ac.il Israel Environment | | info.cern.ch Switzerland (CERN) High-energy physics | | fatty.law.cornell.edu USA Law | | www.cc.ukans.edu USA History | | www.njit.edu USA | +------------------------------------------------------------------+
Using CERN as the entry point you will find information about WWW itself, with an overview of the Web and a catalogue of the databases sorted by subject.
Using WORLD-WIDE WEB
The line mode browser:
The line mode browser is a simple user interface: references are shown as a number in square brackets next to each referenced word. Type the number and hit the RETURN key to follow a reference. For example, here is the beginning of the Subject Catalogue on the CERN server:
So This is a distributed subject catalogue. See also arrangement by service type[1], and other subject catalogues of network information[2]. The World-Wide Web Virtual Library: Subject Catalogue
THE WWW VIRTUAL LIBRARY
Mail to maintainers of the specified subject or www-request@info.cern.ch to add pointers to this list, or if you would like to contribute to administration of a subject area.
See also how to put your data on the web[3]
- Aeronautics Mailing list archive index[4]. See also NASA
- LaRC[5]
- Agriculture See Agricultural info[6], Almanac mail servers[7] the Agricultural Genome[8] (National Agricultural Library, part of the U.S. Department of Agriculture)
- Archaeology[9] Separate list
- Astronomy and Astrophysics[10]
- Separate list.
- 1-64, Back, for more, Quit, or Help:
To access WWW
with the line mode browser, type: www. So The default first document will appear on your screen. From this point, you should be able to navigate through the WWW universe by reading the text and following the instructions at the bottom of the screen. If you want to start with a document other than the default, or if you want to change some other aspect of the usual interaction, a number of command line parameters and options are available. The full format of the www command to invoke the line mode browser is:
+---------------------------------------------------------------+ | | | www [options] [docaddress] [keyword>] | | | +---------------------------------------------------------------+
where: docaddress is the hypertext address of the document at which you want to start browsing.Also keyword the supplied keyword(s) are used to query the index specified by docaddress. A list of matching entries is displayed. Multiple keywords are separated by blanks.
Options are:
- -n non-interactive mode. The document is format and display to the screen. Pages are delimit with form feed characters (FF).
- -listrefs adds a list of the addresses of all document references to the end. Non-interactive mode only.
- -pn sets the page length to n lines. Without a number, makes the page length infinite. Default is 24.
- -wn sets the page width to n columns. The default is 78, 79 or 80 depending on the system.
- -na hides references in the text. Useful when printing out the document .
- -version displays the version number of the software.
The following commands are available
when using a line mode browser either as a local client or as a remote client. Some are disable when not applicable (e.g. Find is enable only when the current document is an index). CAPITAL letters indicate acceptable abbreviation; angle brackets ([]) indicate an optional parameter.
- So Help gives a list of available commands depending on the context, and the hypertext address of the current document.
- Manual displays the on-line manual.
- Quit exits WWW.
- number type in one of the numbers shown in [] and hit the RETURN key to follow the link associated to the reference.
- RETURN hit the RETURN key to display the next page of the current document (without a reference number).
- Up, Down scrolls up or down one page in the current document.
- Top, BOttom goes to the top or the bottom of the current document.
- Back, HOme goes back to the first document you were reading.
- Next, Previous goes to the next or previous document in the list of pointers from the document that led to the current one.
- List gives a numbered list of the links from the current document. To follow a link, type in the number.
- Recall if number is omit, gives a numbered list of the documents you have visited.
- To display one specific document, re-issue the command with number.
- So (Find) keyword queries the current index with the supplied keyword(s). A list of matching entries is display with possible links to further details. Find can be omit if the first keyword its not conflict with another WWW command. Multiple keywords are separate by blanks.
- Go docaddress goes to the document that represnt by the hypertext address, which is interpret relative to the current document.
Extra command available on Unix versions only:
- Print prints the current document, without the numbered document references. The default print command is lpr, but it may be define in your local working environment by the variable WWW_PRINT_COMMAND.