General Web Questions

World Wide Web:


The World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks. Using concepts from earlier hypertext systems, the World Wide Web was invented in 1989 by the English physicist Tim Berners-Lee, now the Director of the World Wide Web Consortium, and later assisted by Robert Cailliau, a Belgian computer scientist, while both were working at CERN in Geneva, Switzerland. In 1990, they proposed building a "web of nodes" storing "hypertext pages" viewed by "browsers" on a network,[1] and released that web in December.[2]


Internet :


The Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite (TCP/IP). It is a network of networks that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by copper wires, fiber-optic cables, wireless connections, and other technologies.






web browser:


A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI) and may be a web page, image, video, or other piece of content.[1] Hyperlinks present in resources enable users to easily navigate their browsers to related resources.


Although browsers are primarily intended to access the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems.


The major web browsers are Windows Internet Explorer, Mozilla Firefox, Apple Safari, Google Chrome, and Opera.


Uniform Resource Identifier:


In computing, a Uniform Resource Identifier (URI) consists of a string of characters used to identify or name a resource on the Internet. Such identification enables interaction with representations of the resource over a network (typically the World Wide Web) using specific protocols. Schemes specifying a specific syntax and associated protocols define each URI.


Relation ship between (URL) & (URN):


Computer scientists may classify a URI as a locator (URL), or a name (URN), or both.


A Uniform Resource Name (URN) functions like a person's name, while a Uniform Resource Locator (URL) resembles that person's street-address. In other words: the URN defines an item's identity, while the URL provides a method for finding it.


The ISBN system for uniquely identifying books provides a typical example of the use of typical URNs. ISBN 0486275574 (urn:isbn:0-486-27557-4) cites unambiguously a specific edition of Shakespeare's play Romeo and Juliet. In order to gain access to this object and read the book, one would need its location: a URL address. A typical URL for this book on a unix-like operating system might look like the file path file:///home/username/RomeoAndJuliet.pdf, identifying the electronic book saved in a file on a local hard disk. So URNs and URLs have complementary purposes.


Uniform Resource Locator :


In computing, a Uniform Resource Locator (URL) is a type of Uniform Resource Identifier (URI) that specifies where an identified resource is available and the mechanism for retrieving it. In popular usage and in many technical documents and verbal discussions it is often incorrectly used as a synonym for URI.[1] In popular language, a URL is also referred to as a Web address.


The Uniform Resource Locator was created in 1990 by Tim Berners-Lee as part of the URI.[2] He regrets the format of the URL. Instead of being divided into the route to the server, separated by dots, and the file path, separated by slashes; he would have liked it to be one coherent hierarchical path. For example, http://www.serverroute.com/path/to/file.html would look like http://com/serverroute/www/path/to/file.html.


Every URL is made up of some combination of the following: the scheme name (commonly called protocol), followed by a colon, then, depending on scheme, a hostname (alternatively, IP address), a port number, the pathname of the file to be fetched or the program to be run, then (for programs such as CGI scripts) a query string[3][4], and with HTML files, an anchor (optional) for where the page should start to be displayed.[5]


The combined syntax looks like:
resource_type://domain:port/filepathname?query_string#anchor


Polymorphism:


In computer science, polymorphism is a programming language feature that allows values of different data types to be handled using a uniform interface. The concept of parametric polymorphism applies to both data types and functions. A function that can evaluate to or be applied to values of different types is known as a polymorphic function. A data type that can appear to be of a generalized type (e.g., a list with elements of arbitrary type) is designated polymorphic data type like the generalized type from which such specializations are made