Computer networking is the practice of connecting two or more computers or computing devices to share data and resources. Networks are created with a combination of computer hardware and software.
A computer network is built upon essential pillars, such as a network card, router and protocols. In any network, users share resources from one device to another, create and store files in one computer and access them from other computers connected to the network. A connected network also allows for the connection of printers, fax machines and scanners to one computer in the network, so that other computers within the network are allowed to use the devices available as well.
There are four main types of networks:
local area network/LAN, wide area network/WAN,metropolitan area network/MAN and wireless local area network/WLAN.
LAN serves a small group of people in a small area such as a single home, small office building or school. Client server or peer-to-peer networking methods may be employed. WAN covers huge geographical areas, such as across states, cities and even across the world, employing leased communication lines. The world’s largest WAN is the Internet.
A WLAN does not use physical media or wires to connect the server with hosts. It transfers data over radio transceivers.
Internet is a global network connecting millions of computers. More than 190 countries are linked into exchanges of data, news and opinions.
A Web site is a related collection of World Wide Web (WWW) files that includes a beginning file called a home page. A company or an individual tells you how to get to their Web site by giving you the address of their home page. From the home page, you can get to all the other pages on their site.
Types of website
- Static
- Dynamic
HISTORY OF INTERNET
The history of the Internet begins with the development of electronic computers in the 1950s. Initial concepts of packet networking originated in several computer science laboratories in the United States, United Kingdom, and France.[1] The US Department of Defense awarded contracts as early as the 1960s for packet network systems, including the development of the ARPANET. The first message was sent over the ARPANET from computer science Professor Leonard Kleinrock's laboratory at University of California, Los Angeles (UCLA) to the second network node at Stanford Research Institute (SRI).
Packet switching networks such as ARPANET, NPL network, CYCLADES, Merit Network, Tymnet, and Telenet, were developed in the late 1960s and early 1970s using a variety of communications protocols.[2] Donald Davies first designed a packet-switched network at the National Physics Laboratory in the UK, which became a testbed for UK research for almost two decades.[3][4] The ARPANET project led to the development of protocols for internetworking, in which multiple separate networks could be joined into a network of networks.
Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) funded the Computer Science Network (CSNET). In 1982, the Internet protocol suite (TCP/IP) was introduced as the standard networking protocol on the ARPANET. In the early 1980s the NSF funded the establishment for national supercomputing centers at several universities, and provided interconnectivity in 1986 with the NSFNET project, which also created network access to the supercomputer sites in the United States from research and education organizations. Commercial Internet service providers (ISPs) began to emerge in the very late 1980s. The ARPANET was decommissioned in 1990. Limited private connections to parts of the Internet by officially commercial entities emerged in several American cities by late 1989 and 1990,[5] and the NSFNET was decommissioned in 1995, removing the last restrictions on the use of the Internet to carry commercial traffic.
In the 1980s, research at CERN in Switzerland by British computer scientist Tim Berners-Lee resulted in the World Wide Web, linking hypertext documents into an information system, accessible from any node on the network.[6] Since the mid-1990s, the Internet has had a revolutionary impact on culture, commerce, and technology, including the rise of near-instant communication by electronic mail, instant messaging, voice over Internet Protocol (VoIP) telephone calls, two-way interactive video calls, and the World Wide Web with its discussion forums, blogs, social networking, and online shopping sites. The research and education community continues to develop and use advanced networks such as NSF's very high speed Backbone Network Service (vBNS), Internet2, and National LambdaRail. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1-Gbit/s, 10-Gbit/s, or more. The Internet's takeover of the global communication landscape was almost instant in historical terms: it only communicated 1% of the information flowing through two-way telecommunications networks in the year 1993, already 51% by 2000, and more than 97% of the telecommunicated information by 2007.[7] Today the Internet continues to grow, driven by ever greater amounts of online information, commerce, entertainment, and social networking.
INTERNET EXPLORER
Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer,commonly abbreviated IE or MSIE) is a discontinued series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year. Later versions were available as free downloads, or in service packs, and included in the original equipment manufacturer (OEM) service releases of Windows 95 and later versions of Windows.
Internet Explorer was one of the most widely used web browsers, attaining a peak of about 95% usage share during 2002 and 2003.[5] This came after Microsoft used bundling to win the first browser war against Netscape, which was the dominant browser in the 1990s. Its usage share has since declined with the launch of Firefox (2004) and Google Chrome (2008), and with the growing popularity of operating systems such as macOS, Linux, iOS and Android that do not run Internet Explorer. Estimates for Internet Explorer's overall market share range from 5.45% to 27.38% or by StatCounter's numbers ranked 3rd, just after Firefox (or even as low as 6th when counting all platforms, after Opera (and behind Safari)[6]), as of August 2016 (browser market share is notoriously difficult to calculate). Microsoft spent over US$100 million per year on Internet Explorer in the late 1990s,[7] with over 1,000 people working on it by 1999.[8][9]
Versions of Internet Explorer for other operating systems have also been produced, including Internet Explorer for Mac and Internet Explorer for UNIX (Solaris and HP-UX), an Xbox 360 version called Internet Explorer for Xbox and an embedded OEM version called Pocket Internet Explorer, later rebranded Internet Explorer Mobile made for Windows Phone, Windows CE, and previously, based on Internet Explorer 7 for Windows Mobile.
On March 17, 2015, Microsoft announced that Microsoft Edge will replace Internet Explorer as the default browser on its Windows 10 devices. This effectively makes Internet Explorer 11 the last release. Internet Explorer will, however, remain on some versions of Windows 10 primarily for enterprise purposes.[10] Starting January 12, 2016, only Internet Explorer 11 is supported with more security than older versions, according to Microsoft.[11][12] Support varies based on the operating system's technical capabilities and its support lifecycle.[13]
The browser has been scrutinized throughout its development for use of third-party technology (such as the source code of Spyglass Mosaic, used without royalty in early versions) and security and privacy vulnerabilities, and the United States and the European Union have alleged that integration of Internet Explorer with Windows has been to the detriment of fair browser competition.
HOME PAGE
A home page or a start page is the initial or main web page of a website or a browser. The initial page of a website is sometimes called main page as well.
Website home page
A home page is generally the main page a visitor navigating to a website from a web search engine will see, and it may also serve as a landing page to attract visitors.[1][2] The home page is used to facilitate navigation to other pages on the site by providing links to prioritized and recent articles and pages, and possibly a search box.[3] For example, a news website may present headlines and first paragraphs of top stories, with links to full articles, in a dynamic web page that reflects the popularity and recentness of stories.[4] Meanwhile, other websites utilize the homepage to attract users to create an account. Once they are logged in, the homepage may be redirected to their profile page. This may in turn be referred to as the "personal home page".[5]A website may have multiple home pages, although most have one.[6] Wikipedia, for example, has a home page at wikipedia.org, as well as language-specific home pages, such as en.wikipedia.org and de.wikipedia.org.
Website structure
The majority of websites have a home page with underlying content pages, although some websites contain only a single page.[7]The uniform resource locator (URL) of a home page is most often the base-level domain name, such as https://wikipedia.org. Historically it may also be found at http://domain.tld/index.html or http://domain.tld/default.html, where "tld" refers to the top-level domain used by the website.[8]
If a home page has not been created for a web site, many web servers will default to display a list of files located in the site's directory, if the security settings of the directory permit.[9] This list will include hyperlinks to the files, allowing for simple file sharing without maintaining a separate HTML file.
Browser home page
A home page also refers to the first page that appears upon opening a web browser, sometimes called the start page, although the home page of a website can be used as a start page. This start page can be a website, or it can be a page with various browser functions such as the display of thumbnails of frequently visited websites. Multiple websites can be set as a start page, to open in different tabs. Some websites are intended to be used as start pages, such as iGoogle (now defunct), My Yahoo!, and MSN.com, and provide links to commonly used services such as webmail and online weather forecasts.[10]INTERNET ADDRESS(URL)
An Internet address uniquely identifies a node on the Internet. Internet address may also refer to the name or IP of a Web site (URL). The term Internet address can also represent someone's e-mail address.
URL is the abbreviation of Uniform Resource Locator. It is the global address of documents and other resources on the World Wide Web. For example, www.webopedia.com is a URL. A URL is one type of Uniform Resource Identifier (URI); the generic term for all types of names and addresses that refer to objects on the World Wide Web.
Parts of a URL
The first part of the URL is called a protocol identifier and it indicates what protocol to use, and the second part is called a resource name and it specifies the IP address or the domain name where the resource is located. The protocol identifier and the resource name are separated by a colon and two forward slashes.WORLD WIDE WEB
The World Wide Web (abbreviated WWW or the Web) is an information space where documents and other web resources are identified by Uniform Resource Locators (URLs), interlinked by hypertext links, and can be accessed via the Internet.[1] English scientist Tim Berners-Lee invented the World Wide Web in 1989. He wrote the first web browser computer programme in 1990 while employed at CERN in Switzerland.[2][3]
The World Wide Web has been central to the development of the Information Age and is the primary tool billions of people use to interact on the Internet.[4][5][6] Web pages are primarily text documents formatted and annotated with Hypertext Markup Language (HTML). In addition to formatted text, web pages may contain images, video, audio, and software components that are rendered in the user's web browser as coherent pages of multimedia content. Embedded hyperlinks permit users to navigate between web pages. Multiple web pages with a common theme, a common domain name, or both, make up a website. Website content can largely be provided by the publisher, or interactive where users contribute content or the content depends upon the user or their actions. Websites may be mostly informative, primarily for entertainment, or largely for commercial, governmental, or non-governmental organisational purposes. In the 2006 Great British Design Quest organised by the BBC and the Design Museum, the World Wide Web was voted among the top 10 British design icons.
A global map showing the availability of the World Wide Web in the 2010s. The regions with the highest level of access, in dark blue, are North America, Europe, Japan and Australia
Electronic mail, or email, is a method of exchanging digital messages between people using digital devices such as computers, tablets and mobile phones. Email first entered substantial use in the 1960s and by the mid-1970s had taken the form now recognised as email. Email operates across computer networks, which in the 2010s is primarily the Internet. Some early email systems required the author and the recipient to both be online at the same time, in common with instant messaging. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect only briefly, typically to a mail server or a webmail interface, for as long as it takes to send or receive messages.
Originally an ASCII text-only communications medium, Internet email was extended by Multipurpose Internet Mail Extensions (MIME) to carry text in other character sets and multimedia content attachments. International email, with internationalized email addresses using UTF-8, has been standardized, but as of 2016 it has not been widely adopted.[citation needed]
The history of modern Internet email services reaches back to the early ARPANET, with standards for encoding email messages published as early as 1973 (RFC 561). An email message sent in the early 1970s looks very similar to a basic email sent today. Email played an important part in creating the Internet,[2] and the conversion from ARPANET to the Internet in the early 1980s produced the core of the current services.
This screenshot shows the "Inbox" page of an email system, where users can see new emails and take actions, such as reading, deleting, saving, or responding to these messages
ONLINE CHAT
Online chat may refer to any kind of communication over the Internet that offers a real-time transmission of text messages from sender to receiver. Chat messages are generally short in order to enable other participants to respond quickly. Thereby, a feeling similar to a spoken conversation is created, which distinguishes chatting from other text-based online communication forms such as Internet forums and email. Online chat may address point-to-point communications as well as multicast communications from one sender to many receivers and voice and video chat, or may be a feature of a web conferencing service.
Online chat in a less stringent definition may be primarily any direct text-based or video-based (webcams), one-on-one chat or one-to-many group chat (formally also known as synchronous conferencing), using tools such as instant messengers, Internet Relay Chat (IRC), talkers and possibly MUDs. The expression online chat comes from the word chat which means "informal conversation". Online chat includes web-based applications that allow communication – often directly addressed, but anonymous between users in a multi-user environment. Web conferencing is a more specific online service, that is often sold as a service, hosted on a web server controlled by the vendor.
SOCIAL NETWORKING
A social network is a social structure made up of a set of social actors (such as individuals or organizations), sets of dyadic ties, and other social interactions between actors. The social network perspective provides a set of methods for analyzing the structure of whole social entities as well as a variety of theories explaining the patterns observed in these structures.[1] The study of these structures uses social network analysis to identify local and global patterns, locate influential entities, and examine network dynamics.
Social networks and the analysis of them is an inherently interdisciplinary academic field which emerged from social psychology, sociology, statistics, and graph theory. Georg Simmel authored early structural theories in sociology emphasizing the dynamics of triads and "web of group affiliations".[2] Jacob Moreno is credited with developing the first sociograms in the 1930s to study interpersonal relationships. These approaches were mathematically formalized in the 1950s and theories and methods of social networks became pervasive in the social and behavioral sciences by the 1980s.[1][3] Social network analysis is now one of the major paradigms in contemporary sociology, and is also employed in a number of other social and formal sciences. Together with other complex networks, it forms part of the nascent field of network science.
SURFING THE INTERNET
Using a web browser to search through the many home pages that make up the world wide web - also used to describe searching through the Internet as a whole.
Usually involves an individual browsing through the internet, whilst not looking for anything in particular.
USING SEARCH ENGINES
This is a list of search engines, including web search engines, selection-based search engines, metasearch engines, desktop search tools, and web portals and vertical market websites that have a search facility for online databases. For a list of search engine software, see List of enterprise search vendors.
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