Navigator Web

Characteristics of the software

The Web navigator is composed of a driving of returned of the Standards of the Web, of a Interface user and incidentally of a manager of extensions called Plugin S .

User interface

For the large majority of the navigators on the market, the user interface is made up of a zone of posting possibly managed in the form of miters, of a bars pull-down menus, of a Barre of tools and of a bar of state.

The bar of menus shelters the favorites (or marks pages), the orders of the files (opening, closing), the options of configuration, etc

The Barre of tools contains the Barre of address, the button S of navigation (preceding page, following page, to bring up to date,…), etc

The bar of state posts the reports of posting, Téléchargement S (for IE) and other information like the blocking of the popups for Firefox.

Use

The principal function of a Web navigator is to allow the consultation of information available (“resource” in the terminology of the Web) on the World Wide Web. The principal stages of the consultation of a resource are the following ones:

the user gives to the Web navigator the Adresse Web of the resource to be consulted. There exist three manners of giving a Web address:
*taper oneself the Address Web in the Bar of address of the navigator;
to *choisir a resource in the list of the favorites (or mark-page or bookmark ), knowing that with each favorite is associated a Web address;
*suivre a Hyperlink, knowing that with each hyperlink a Adresse Web is associated.
the navigator is connected to the Web server lodging the resource concerned and the downloads. The Communication protocol generally used is HTTP.
the engine of returned of the navigator treats this resource, downloads the possible associated resources and posts the result on the screen of the user.

Functionalities

Returned with the screen

A Web navigator must be able, at least, to post the text of a Web page. A navigator in Mode text often does not post anything more. The navigators usually used function however as a graphic mode and are able to use a worked out typography, to add images in the text, to play of the music and animations and to interact with the actions of the user.

A Web page is a text written in the data-processing language Hypertext Markup Language (HTML) which gives to the navigator the text to be posted as well as the general structure of the page layout: titles and paragraphs, lists, tables. The page layout can be refined by the use of Style sheets in cascade (CS): margins, alignments, spacings, colors, edges, etc

The position of the images in a Web page is given by language HTML. The images are generally in a Format of data among the three following: GIF, JPEG or png.

Returned on other devices

The majority of the navigators make it possible to print the Web pages in black and white or colors. Moreover particular devices can be used to mitigate a visual or driving handicap.

Scripts

In the context of the Web, a script is a Computer program integrated into the Web page and carried out by the navigator. A script allows simple tasks like checking the data entered a form, managing menus or to react to displacements of the pointer of mouse. The principal language of script side customer is the JavaScript. This language is standardized by ECMA under the name of ECMAScript.

See also: Dynamic HTML, AJAX, Javascript

Plugins

The navigators being able with difficulty to manage the whole of the formats of data existing and future, the editors of navigators were brought to develop a mechanism of control or plug-ins which take the name of Plugin S , ActiveX for Internet Explorer.

Those make it possible to post directly in the window of the navigator of the data of formats very different energy from documents pdf with multimedia contents. This mechanism also makes it possible to use computer programming languages side customer like animations Flash or the Applet S Java. The broad diffusion of a plugin being necessary so that a format of data has a chance to take a lead in the Web, one will very often find some in free remote loading on the sites of security companies of software making it possible to create a type of particular contents.

Protocols

Protocol HTTP is not the only one that a Web navigator can use. It can also manage the transfers of file using ftp or WebDAV, and establish protected connections by using HTTPS (HTTP on SSL). These Communication protocols is generally standardized by IETF.

Vulnerabilities

Because of his strong diffusion in the world the navigator is a privileged target of the pirates eager to harm the Internaute S.

The Net surfer is threatened via his navigator to be victim of the following attacks:

profilisation and analyzes behavioral at ends of resale marketing
flight of personal data per access to its files
swindle by Phishing
crash landing of its computer by bug of the navigator

A navigator consists of various modules realizing of the well defined functions and having each one their own vulnerabilities:

an interpreter of URL vulnerable to the attacks by phishing
an interpreter of code HTML or XHTML (more recent) which can make to a bad interpretation of the instructions of description
an interpreter of Langage of script (JavaScript, VBScript…) vulnerable to the loops without ends, exploitations of bugs
an environment of execution of applications (Applet Java, ActiveX, Plugin S)
a Bar of tools

History of the navigators Web

The Web navigators are Logiciel S complexes and in constant evolution, mainly on the level of safety, because of new viruses, towards, malevolent spywares and other scripts do not cease being born, but also on the level of the functionalities bus of new the standard or the revisions of the standards is born regularly.

The first navigator editor date of 1990. Developed in two months, it was called WorldWideWeb (renamed nexus later), and was developed in Objective C on NeXT.

The first navigator, stable, functional, multiplateformes and especially widely diffused, were NCSA Mosaic, in 1993.

As of 1995, Netscape Navigator became the navigator dominating, developed by Marc Andreessen, the former head of the development of Mosaic.

In 1995 also Internet Explorer 1 left Microsoft.

Starting from 2000, and after several years of War of the navigators, it is Internet Explorer which became the navigator more used. The reason is mainly the supply pre-installed within Microsoft Windows, example of the Dominant position abuses charged at Microsoft, which allow him to support the diffusion of its software to the detriments of its competitors thanks to its privileged position of supplier of the operating system.

As from 2005, one notes a regression on behalf of market of Internet Explorer, especially for the benefit of Mozilla Firefox.

Many other navigators, called alternative navigators, share the crumbs, in particular those based on the driving of returned Gecko of Mozilla (of which Mozilla Firefox, SeaMonkey, Epiphany, Flock, IceWeasel and Galeon), Presto (Suite Internet Opera version 7 and more, Opera Mobile, Opera Mini, Wii Internet Chanel, Nintendo DS browser, Sony Mylo), and those based on KHTML of the project KDE (Konqueror, Safari of Apple and OmniWeb of OmniGroup based on a Fork of KHTML).

Moreover, since the medium of the Années 1990 there always existed a multitude of other more or less popular navigators.

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