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Review of Web Technologies

Introduction
Web technology is related to the interface between client and server.This information include markup language,programming interfaces and languages, and standards for document identification and display. In general web technology incorporates tools and techniques for web development.Web Development is a term for the work involved in developing a web site for World Wide Web(WWW) . This can include web design, web content development, client liaison, client-side/server-side scripting, web server and network security configuration, and e-commerce development.It can range from developing a simple static page to most complex web-based application.

Web design is a term used to encompass the way that content (usually hypertext or hypermedia) is delivered to an end-user through the World Wide Web, using a web browser or other web-enabled software is displayed. The purpose of web design is to create a website—a collection of online content including documents and applications that reside on a web servers. It may include text, images, sounds and other content, and may be interactive.

For the typical web sites, the basic aspects of design are:
The content: the substance, and information on the site should be relevant to the site and should target the area of the public that the website is concerned with.
The usability: the site should be user-friendly, with the interface and navigation simple and reliable.
The appearance: the graphics and text should include a single style that flows throughout, to show consistency. The style should be professional, appealing and relevant.
The structure: of the web site as a whole.

Internet and its Evolution
The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide.It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local global scope, that are linked by a broad array of electronic and optical networking technologies. The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support electronic mail.
The history of internet begins in the 1950s with the development of the electronic computer.

  1. 1957
    USSR launches Sputnik into space and, with it, global communications. The United States government creates the Advanced Research Projects Agency (ARPA) in response to Sputnik launch in 1958.
  2. 1961
    Leonard Kleinrock at MIT wrote a paper called”information flow in large communication Nets” which communicated his theory and concept for packet switching.
  3. 1965
    Lawrence Roberts (MIT) and Thomas Marill get an ARPA contract to create the first wide-area network (WAN) connection via long distant dial-up between a TX-2 computer in Massachusetts and a Q-32 computer in California. The system confirms that packet switching offers the most promising model for communication between computers.
  4. 1969
    The ARPANET is born .linking four nodes university of California at loss Angeles,Stanford research institute((RSI). University of California at Santa Barbara and university of Utah the network is wired together via 50 kbps circuit. First message sent across the network was supposed to have been “login”.
  5. 1970
    Network control protocol (NCP) is designed allowing connection and flow control between process running on different hosts.
  6. 1972
    email is introduced . Ray Tomlinson of BBN invents the email program to send messages across a distributed network.The "@" sign is chosen from the punctuation keys on Tomlinson's Model 33 Teletype to separate local from global emails, making "user@host" the email standard.
  7. 1973
    Development begins on TCP/IP protocol by a group headed by Vint Cerf (Stanford) and Robert Kahn (DARPA). The new protocol will allow diverse computer networks to interconnect and communicate with each other.
  8. 1974
    Vint Cerf and Robert Kahn publish "A Protocol for Packet Network Interconnection" which specifies in detail the design of a Transmission Control Program (TCP) and coins the term “Internet” for the first time.
  9. 1978
    The Bulletin board system(BBS) is developed and spam is born.
  10. 1983
    Paul Mockapetris expands the Internet beyond its academic origins by inventing the Domain Name System (DNS). John Klensin helps facilitate early procedural and definitional work for DNS administration and top-level domain definitions.
  11. 1988
    Internet relay chat(IRC) is developed .
  12. 1989
    www proposal was written by Tim burners-lee to convince CERN that a global hypertext system was in their best interest.
  13. 1990
    First commercial dial-up internet provider was launched also the code for www was written by Tim Berners-Lee ,based on his proposal from the year before along with the standard for HTML,HTTP,and URLs
  14. 1991
    the first web page is created and its purpose was to explain what the www was.it was purely text-based site with lots of highlighted linked embedded into a text which links user to another address and pages .In the same year the first search protocol ,that examined file content instead of just file names was launched called Gopher.
  15. 1993
    Mosaic-the first graphical web browser for the general public was introduced .Also the same year marked the beginning of the .gov and .org domain name for government and UN uses.
  16. 1995
    The first SSL(source socket layer ) encryption was developed by Netscape making it safer to conduct financial transaction which involved credit card payments online this saw the introduction of E-bay and amazon two of the biggest e-commerce business name on the internet. Java and javascript was first introduced in public in 1995 originally called LiveScript it was deployed as a part of Netscape
  17. 1996
    Dr. Henning Schulzrinne co-develops key protocols that enable Voice over the Internet protocol (VoIP). Also in same year Brewster Kahle Founds Internet Archive; Email Surpasses Postal Mail.
  18. 1998
    Michael Roberts becomes the first president and CEO of the Internet Corporation for Assigned Numbers (ICANN).

Client server technology
In a computing model powerful personal computer are connected together with one or more servers.Clients are the powerful personal computer that is a part of a network which requestsfor the service.also called service requestor.Server is a network computer dedicated to common functions that the client computer on the network .it is also called service provider.Web is based on client/server technology. Web servers are included as part of a larger package of internet andintranet related programs for serving e-mail, downloading requests for FTP files and building and publishing web pages.In the client/ server model single machine can be both client and the server The client/ server model utilises a database server in which RDBMS user queries can be answered directly by the server.it reduces the network trafficby providing a query response to the user rather than transferring total files. The client/ server model improves multi-user updating through a graphical user interface (GUI) front end to the shared database. In client/ server architectures client and server typically communicate through statements made in structured query language (SQL).

Client_server_technology
Client/Server model

WWW
WWW stand for world wide web.It is a system of interrelated hypertext document that can be accessed via internet.world wide web ,or simply web is an information sharing modelthat is built on top of the Internet.It is a collection of image,text sounds and other resourcesinked by hyperlinks and URLs,which can be viewed using browser software.uses the HTTP protocol to transmit data. Web services, which use HTTP to allow applications to communicate in order to exchange business logic, use the Web to share information. The Web also utilizes browsers, such as Internet Explorer or Firefox, to access Web documents called Web pages that are linked to each other via hyperlinks.

Web pages
A web page is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext links. Web pages frequently subsume other resources such as style sheets, scripts and images into their final presentation.they are requested and served from web servers using Hypertext Transfer Protocol (HTTP).It may consist of files of static text and other content stored within the web server's file system (static web pages), or may be constructed by server-side software when they are requested (dynamic web pages). Client-side scripting can make web pages more responsive to user input once on the client browser.

Web sites
web site is a collection of related web pages containing images, videos or other digital assets.A website is hosted on at least one web server, accessible via a network such as the Internet or a private local area network through an Internet address known as a Uniform Resource Locator. All publicly accessible websites collectively constitute the World Wide Web. web site can be categorized into two types, Static web site and dynamic web site.

Static website
static websites contain fixed number of web pages and format of web page is fixed which delivers information to the client.This kind of web site is created using HTML and CSS coding on simple text editor like notepad. Static sites never use database connectivity.Static site use for provide some information to the clients like an organization or institute website.Static sites are easy to develop and a bit experienced people can develop it.

Dynamic website
change the web page contents dynamically while the page is running on client's browser. This kind of websites use server- side programming like PHP, Asp.NET. and JSP etc. to modify page contents on run time.Dynamic websites use client side scripting for prepare dynamic design and server- side code to handle event, manage session and cookies, and storing and retrieving data from database.Dynamic websites are not easy to develop because require qualify developers to create it, manage it, test it and maintain security of application and database.

URI
URI stands for Uniform Resource Identifier is a string of characters used to identify a resources. A URI identifies a resource either by location, or a name, or both.A URI has two specializations known as URL and URN.
URL stands for Uniform Resource Locator. It is a subset of the Uniform Resource Identifier (URI which is used by a web browser to identify the location of content on the web. It can be http://, or ftp://.
URN Stands for Uniform Resource Name. It is a Uniform Resource Identifier (URI) that uses the URN scheme, and does not imply availability of the identified resource. Both URNs and URLs are URIs, and a particular URI may be both a name and a locator at the same time.

Web server
Web server is a computer system which receives the HTTP requests via TCP, which are used to distribute information on world wide web. commonly a web browser or web crawler, initiates communication by making HTTP request for a specific resource and the server responds with the content of that resource or an error message if unable to do so. The main function of a web server is to store, process and deliver web pages to clients. The communication between client and server takes place using the Hypertext Transfer Protocol (HTTP). Pages delivered are most frequently HTML documents, which may include images, stylesheets and scripts in addition to text content.
Web servers are not only used for serving the World Wide Web. They can also be found embedded in devices such as printers, routers, webcams and serving only a local network. The web server may then be used as a part of a system for monitoring and/or administering the device in question. This usually means that no additional software has to be installed on the client computer, since only a web browser is required (which now is included with most operating systems). Apache,Internet information Server(IIS),tomcat are some example of web server.

Web Client
It is a software application capable of communicating with Web servers, requesting and receiving information from them, and processing it for display or other uses.It is used to create a HTTP request message and for processing the HTTP response message.Any web client is designed to directly support user access to web servers is known as user agent. web browser is one kind of web client.Web browsers can run on desktop or laptop computers. Some of the browsers are: Internet Explorer, Mozilla, FireFox, Chrome, Safari, Opera, Netscape Navigator.

Web Browser
Web browser is a software application used to locate, retrieve and display content on the World Wide Web, including Web pages, images, video and other files. As a client/server model, the browser is the client run on a computer that contacts the Web server and requests information. The Web server sends the information back to the Web browser which displays the results on the computer or other Internet-enabled device that supports a browser.

SMTP
SMTP stands for Simple Mail Transfer Protocol..It is an Internet standard for electronic mail (e-mail) transmission across Internet Protocol (IP) networks.SMTP by default uses TCP port25.. SMTP is aconnection-oriented,text-basedprotocol in which a mail sender communicates with a mail receiver by issuing command strings and supplying necessary data over a reliable ordered data stream channel, typically aTransmission Control Protocol(TCP) connection.SMTP is a delivery protocol only. It cannot pull messages from a remote server on demand. Other protocols, such as the Post Office Protocol (POP) and the Internet Message Access Protocol (IMAP) are specifically designed for retrieving messages and managing mail boxes. However, SMTP has a feature to initiate mail queue processing on a remote server so that the requesting system may receive any messages destined for it.Many mail servers now support Extended Simple Mail Transfer Protocol (ESMTP), which allows multimedia files to be delivered as e-mail.

POP
POP stands for post office protocol.It is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection. Virtually all modern e-mail clients and servers support POP. The POP protocol has been developed through several versions, with version 3 (POP3).POP3 allows an email client to download an email from an email server. The POP3 protocol is simple and does not offer many features except for download. Its design assumes that the email client downloads all available email from the server, deletes them from the server and then disconnects. POP3 normally uses port 110.

References

  1. course hero. <https://www.coursehero.com/file/13523158/AAA-Web-Design-for-Verizon-Wireless-IS535/>.
  2. internet hall of fame. <http://www.internethalloffame.org/internet-history/timeline>.
  3. wikipedia. <https://en.wikipedia.org/wiki/Client–server_model>.
  4. threadsys. <http://www.threadsys.com/index.php/2015/09/16/difference-between-static-and-dynamic-websites/>.
  5. hmailserver. <https://www.hmailserver.com/documentation/latest/?page=whatis_pop3imapsmtp>.
  6. pabi pedia. <http://pabipedia.wikidot.com/simple-mail-transfer-protocol-smtp>.

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