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"World Wide Web" - WWW
"World Wide Web" - WWW WWW (World Wide Web) - hypertext technology. It was with the advent of WWW technology that the rapid development of the Internet began during the 90s.
W W W The World Wide Web is a network of interconnected documents. net, ca, us com, org mil, gov, edu jp, cn, tw, au de, uk, it, pl, fr br, kr, nl unknown
Internet servers that implement WWW technology are called Web servers, and documents implemented using WWW technology are called Web pages. The World Wide Web is hundreds of millions of Internet servers containing Web pages that use hypertext technology.
The web page may contain information presented in various forms: text, graphics, video, sound, animation. Web browsing is carried out with the help of special viewer programs - browsers. Currently, the most common browsers are Internet Explorer, Netscape Navigator, Opera, Mozilla.
Web page A web page is an independent document containing hyperlinks and having the htm (html) extension.
Hyperlink A hyperlink is a fragment of a Web document that establishes a connection between objects and allows you to navigate to other Internet objects: files, web pages or file fragments. When you move the mouse pointer over a hyperlink, the pointer turns into a pointing finger.
You can find a Web page on the Internet or make a link to it using the universal resource locator (page address). Universal Resource Locator (URL-Universal Resource Locator) includes a way to access the document, the name of the server where the document is located, and the path to the document (file).
The method of accessing a document is determined by the information transfer protocol used. Web pages are accessed using the Hyper Text Transfer Protocol (HTTP).
For example, for the initial Internet Explorer Web page, the Uniform Resource Locator will take the form http://home.microsoft.com/intl/ru and consists of three parts: http:// - access protocol home.microsoft.com - server name /intl /ru - path to the file
Web server Web server - a server on the Internet that provides hosting - the allocation of disk space on the server to host websites and provide the ability to view them.
URL - the address of the picture
HTML Web pages are created using the html language (H yper T ext M arkup L anguage - Hypertext Markup Language). A document created using the HTML hypertext markup language contains the source text of the document, including special control characters - tags (tag).
HTML Code of the Web Page
Task 1 The test.edu server hosts the demo.net file, which is accessed via the http protocol. Fragments of the address of this file are encoded with the letters A, B ... G (see table). Write down the sequence of these letters that encodes the address of the specified file on the Internet. A test B demo C:// D / D http E.edu G.net
Task 2 The in fo .edu server hosts the exam.net file, which is accessed via the http protocol. Fragments of the address of this file are encoded with the letters a, b, c ... g (see table). Write down the sequence of these letters that encodes the address of the specified file on the Internet. a info b / c .net d .edu e http f exam g://
Task 3 Access to the index.html file hosted on the www.ftp.ru server is carried out via the http protocol. The table shows fragments of the address of this file, denoted by letters from A to 3. Write down the sequence of these letters corresponding to the address of this file. A .html B www. C / D ftp E.gu E http W index Z://
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Content. The concept of the world wide web. Story. Transferring information from computer to computer. Basic concepts. World Wide Web. Creation of Web pages (HTML). Hyperstructure WWW Browser. Conclusion. Internet.
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The concept of the world wide web. The World Wide Web is a distributed system that provides access to interconnected documents located on various computers connected to the Internet. The word web and the abbreviation WWW are also used to refer to the World Wide Web. The World Wide Web is made up of hundreds of millions of web servers. Most of the resources on the World Wide Web are based on hypertext technology. Hypertext documents hosted on the World Wide Web are called web pages. Multiple web pages linked common theme, design, as well as linked together and usually located on the same web server, is called a website. To download and view web pages, special programs are used - browsers.
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Story. The World Wide Web was originally created in the United States as a network of computers from the United States Department of Defense. The network was developed in such a way that if some sections or nodes of the network were damaged, it would remain operational. With the enlargement of the network, the increase in the speed of data transfer, the World Wide Web began to be used not only for military, government, educational and scientific, but also for commercial purposes. The World Wide Web has stepped far beyond the US.
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Transferring information from computer to computer. With the help of telephone wires, through an automatic telephone exchange; For communication between large computer networks, permanent leased communication lines are established. With the help of satellites located in geostationary orbit at an altitude of 40,000 km. over the ground.
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Basic concepts. The Internet is a single global computer network. E-mail is the sending and receiving of messages in a matter of seconds. A teleconference is the ability of the Internet to read and send messages for public discussion www is rich graphics, sound, video information, these are the most Hi-tech Providers - providers of network services. Remote access - this service allows you to use your computer to perform any actions with data located on a remote computer.
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World Wide Web. The World Wide Web is a worldwide distributed Information system with hyperlinks, existing on the technical basis of the World Wide Web. The World Wide Web is only 22 years old. The World Wide Web (WWW) was born on August 6, 1991. On this day, Tim Berners-Lee, who worked for European Center Nuclear Research in Geneva (Switzerland), published a brief description of the WWW project. Tim Berners-Lee
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Creation of Web pages (HTML). Web pages are created using Hyper Text Markup Language (HTML). At the heart of this language are control tags (more on that in the next chapter). Web pages may contain different kind information. Dynamic HTML uses the Document Object Model to easily update web pages on the Internet (and hyperlinks can also be created using JavaScript, VBScript, and ActiveX controls). A thematically related group of Web pages is called a Web site.
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Spiders (lat. Araneae, Aranei) - a detachment of arthropods, which has about 42 thousand modern and about 1.1 thousand fossil species. The group is ubiquitous. Spiders are obligate predators, feeding primarily on insects or other small animals.
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The choice of the cross-spider as a subject of study may surprise many. But after all, we often repeat - "the amazing is near." Here are the spiders - the eternal companions of man. What do we know about them. In my work, I studied only one species from a large order of spiders - Araneus diadematus.
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The object of the study is a spider-cross. The subject of the study is the web The purpose of the study is to find out why the cross spider creates a cobweb and how it learns about insects getting into it. Research objectives: 1. To identify and record the facts of catching insects by spiders. 2. Determine and fix the spider's web, its shape and frequency of its renewal. 3. To study the nature of the destruction by spiders of insects caught in the web. Hypothesis. Spider-cross - uses a web to catch insects, which are its food. the spider-cross determines if it enters the prey network by the vibration of the web.
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In nature, cross-spiders are considered especially useful for humans. After all, they destroy insects that give us trouble. It is for this purpose that residents of tropical countries have crosses at home. It is not difficult to see them in the forest, in thickets of bushes or tall grass, where they weave their unusual large web. Very often, the crosses themselves settle in houses, in attics and balconies. The spider-cross will not dare to attack a person or bite him.
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On the upper side of the abdomen of the cross, you can see light brown or white spots that form a cross. Which gave the name to this species. The cross eats small insects, for example, flies, less often bees and wasps. Representatives of Araneus diadematus cannot digest food themselves, therefore external digestion is characteristic of them. The oral apparatus is of a piercing-sucking type. The spider launches digestive juices into the body of the victim in the network, which slowly digest it. The cross is left to suck out the nutrient mixture.
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Male spiders are smaller than females. When courting, the male spider, so that his girlfriend does not eat him, carefully approaches the edge of the web and pulls the threads with his front legs, waiting for the female to answer him with the same movements. And only after that the gentleman decides on a date in the hope of not being eaten. After mating, the spider dies. The female weaves a special cocoon for eggs from the web (lays in autumn). For some time she wears a cocoon on herself. Then he hides it in a secluded place. Juvenile spiders appear in spring.
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What does a cross spider see? Surely few people thought about what feelings this type of spider has. If we talk about vision, then their device is quite complicated, so it is difficult for a person to imagine what exactly and how a spider sees. The cross has as many as four pairs of eyes directed in different directions. In this way, a wide view opens up to him. The world for them it is seen in contours, shadows, movements.
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Nutritional features Cross-spiders are distinguished by their appetite. It is known that such a spider can eat about five insects per day. The lifestyle of the cross spider is hunting. Cross spiders feed on insects, mainly flies and mosquitoes. Having caught the victim, the spider plunges its sharp upper jaws into it and injects a paralyzing poison into the body of the victim. Hungry cross pounces on the caught prey instantly. If he is full, he drags his prey to a secluded place for a rainy day. If there is an insect inedible for him in the nets of the cross, he can cut off the cobwebs and release it.
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Properties of the web Spider silk is produced by special glands; Seven types of arachnoid glands are known to produce different filaments, but none of the spiders has all seven types at once. Spider silk combines two wonderful properties - strength and elasticity. A web of webs is capable of stopping an insect flying at full speed.
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Spider web The spider-cross, to build its circular trapping web, releases a long thread. The web is pulled out from special spider warts. These glands are located at the end of the abdomen and each of them contains about a hundred arachnoid tubes. The most difficult task at this point is attaching the first thread. Araneus diadematus sits and waits for the wind to blow and carry its free end of the hanging thread to the place where it will stick. And only after that the spider proceeds to create a frame of radial rays. The sticky thread consists of twisted very thin fibers covered with a layer of mucous enzyme. The web is several times stronger than natural silk thread. .
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From the point of view of chemistry, the web is a complex protein polymer - fibroin, which quickly hardens in the air in the form of the thinnest threads. The spider can produce several different types cobwebs with different properties: dry and thick - for the frame, silky and soft - for the cocoon, thin and sticky - for the trapping spiral. Why does the spider itself not stick to its web? Everything is very simple - it runs only along non-sticky threads, and diligently avoids touching sticky spirals.
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The web of the cross has exactly 39 radii, 1245 points of attachment of the radii to the spiral and 35 turns of the spiral - no more, no less. The triangular frame is the basis of the future web. Inside this frame, the spider extends several threads that intersect in the center. The spider marks the center of the web with a lump and begins to stretch all its numerous radii from it, fastening them with a spiral thread, and then laying trapping threads. At the intersection points of the spiral and the radius, the spider binds them with its legs.
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Note that the angles between all radii and the distance between the coils of the web are strictly constant. How does such a small creature manage to maintain its web in strict accordance with the geometry? To do this, after all, at least the simplest measuring device is needed. And, imagine, the spider has it. This is his first pair of legs, which can serve as a scale ruler. Working on the web, the cross regularly checks the distance between the spirals. His natural instrument is so accurate and reliable that it allows him to work in pitch darkness. The last chord of creating a web will be a signal thread, the end of which is laid to the spider's shelter. It takes a spider several hours of painstaking work and about 20 meters of web to build the entire web.
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In addition, the web serves as a kind of sensor that helps them hunt. I think each of us has seen how some insect gets into the web of the spiders that live in our homes, which begins to flutter and is soon discovered by the spider. Prey, falling into such a web, creates a vibration that reaches the spider. Spiders have a very well developed tactile sense, and they easily understand where these vibrations come from. Hypothesis - the spider uses a spider web to catch insects that are its food. The spider-cross determines if it enters the prey web by the vibration of the web.
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Interesting Facts about spiders The Black Widow spider lives up to its name: the female kills the male after mating. However, representatives of other types of spiders also have a tendency to kill their admirers. Therefore, they can be considered "black widows." The spider may lay eggs in clothing stored in a warehouse; can engage in laying eggs and when transporting clothes. Therefore, 90% of the clothes we buy contain spider eggs. The venom of the black widow spider is more toxic than that of the rattlesnake. 28 cm - the length of the largest spider; half a millimeter is the smallest. 30 years is not the lifespan limit for spiders. In the frozen amber, an ancient web was found, the age of which is 100 million years. More than once they tried to reproduce the web in laboratories. All attempts failed. The diameter of the web of the orb-weaving spider is 7 meters. The web, the length of which will coincide with the length of the girth of the Earth's equator, will weigh only 340 g. With the help of a web, the thickness of which is equal to the thickness of a pencil, you can stop the Boeing.
