Internet Databases Introduction-: The expansion of internet and intranet enabled the user to access a large number of data sources available. One of major achievements of this expansion is E commerce which include purchasing of items ranging from a small pens,books,to all other types of consumer goods through internet. Various site are available which provide the on line purchasing facility to a number of customers. All these sites are stores a large part of their data in database system since DBMS provide fast,reliable and efficient access to data which is the ultimate needs of electronic commerce and other business application.
WWW(World Wide Web)-: WWW is a graphical internet service that provide a network of interactive documents and software to access them. It allows computer user to locate and view multimedia based documents.Web presents the information as a series of “documents” often referred to as web pages which are linked together through “hyperlink”. These hyperlinks allow the user to navigate from one documents to another that may be located on different servers. The user can use browser to navigate the web.
There are some terminology use in WWW.
Browser-: It is a client software that allows user to display and interact with hypertext documents. Widely used web browser are internet explorer and Netscape browser.
Web Server -: Web server is a programme that response to the request from web browser by accepting URL’s and returning the corresponding documents. It is the place where web pages reside.Some popular web servers are internet Information server(IIS) from Microsoft,Intra Network from Novell and fast track from Netscape.
URL(Uniform Resource Locator) -: It is a web addressing schema that gives exact location of internet resources documents. Any link from one documents to another is always implemented by using URL . A URL contain information about the location of the document typically a URL has Three parts.
- Name of the protocol used to access the resources.
- The host computer where the resources is located.
- The path name of the resources itself on the host computer.
Some of the most important URL are here
HTTP URL– It’s full name of hyper text transform protocol. This URL is used for returning HTML(hyper text markup language) documents on the world wide web. As like If a File ‘ Index.html’ has to retrieved from the directory or home on HTTP server http://www.netnic.org the corresponding URL would be : http://www.netnic.org
FTP URL-: File Transfer Protocol is used to transfer files from the server to machine and vice versa for example to access a documents called netnic.txt on FTP server”net.edu” in the directory ‘nic’. The url would be as like ftp://net.edu/nic/netnic.txt
News URL-: It is used to access any of the Usenet newsgroups as like to access the newsgroups ‘new technologies ‘ the following the url can be used as like news://new.technologies
File URL-: This url is used to access files on the local disk for example The url to access the documents “home.html” at the root of hard disk on our machine would be as file://localhost/c:/home.html
Working of web-: A html link contain a url which identifies the site containing linked file. On selecting the link web browser connects to web server of specified location using a protocol called http. Web server returns a file to web server which checks the file types by examining the extension of the file on client side display the page in proper format.