Web Browser

A web browser or internet browser is software application for retrieving, presenting and traversing information resources on the WWW.
An information resource is identified by a Uniform Resource Identifier (URL) and may be a web page, image, video, or other piece of content. Hyperlinks present in resource enable user to easily navigate their browser to related resource.

Although browser are primarily intended to access the WWW, they can also be used to access information provided by web servers in private networks or files in file system. Some browser can also be used to save information resources to file system.

User interface
Most major web browsers have these user interface elements in common:

• Back and forward buttons to go back to the previous resource and forward again.
• A history list, showing resources previously visited in a list (typically, the list is not visible all the time and has to be summoned).
• A refresh or reload button to reload the current resource.
• A stop button to cancel loading the resource. In some browsers, the stop button is merged with the reload button.
• A home button to return to the user's home page.
• An address bar to input the Uniform Resource Identifier (URL) of the desired resource and display it.
• A search bar to input terms into a search engine.
• A status bar to display progress in loading the resource and also the URI of links when the cursor hovers over them, and page zooming capability.
• Major browsers also possess incremental find features to search within a web page.

 

Function:

• The primary purpose of a web browser is to bring information resources to the user. This process begins when the user inputs a Uniform Resource Identifier (URL) for example http://www.google.com/, into the browser.
• Once the resource has been retrieved the web browser will display it.
• HTML is passed to the browser's layout engine to be transformed from markup to an interactive document.
• Aside from HTML, web browsers can generally display any kind of content that can be part of a web page.
• Information resources may contain hyperlinks to other information resources. Each link contains the URI of a resource to go to. When a link is clicked, the browser navigates to the resource indicated by the link's target URI, and the process of bringing content to the user begins again.
• All major web browsers allow the user to open multiple information resources at the same time, either in different browser windows or in different tabs of the same window. Major browsers also include pop-up blockers to prevent unwanted windows from "popping up" without the user's consent.
• Most web browsers can display a list of web pages that the user has bookmarked so that the user can quickly return to them.

Internet and E-Commerce

According to the editor-in-chief of International Journal of Electronic Commerce, Vladimir Zwass, Electronic commerce is sharing business information, maintaining business relationships and conducting business transactions by means of telecommunications networks. Electronic commerce (e-commerce) remains a relatively new, emerging and constantly changing area of business management and information technology. According to Zwass, electronic commerce has been re-defined by the dynamics of the Internet and traditional e-commerce is rapidly moving to the Internet.

With the advent of the Internet, the term e-commerce began to include:

• Electronic trading of physical goods and of intangibles such as information.
• All the steps involved in trade, such as on-line marketing, ordering payment and support for delivery.
• The electronic provision of services such as after sales support or on-line legal advice.
• Electronic support for collaboration between companies such as collaborative on-line design and engineering or virtual business consultancy teams.

Some of the definitions of e-commerce often heard and found in publications and the media are:

• Electronic Commerce (EC) is where business transactions take place via telecommunications networks, especially the Internet.
• Electronic commerce describes the buying and selling of products, services, and information via computer networks including the Internet.
• Electronic commerce is about doing business electronically.
• E-commerce, ecommerce, or electronic commerce is defined as the conduct of a financial transaction by electronic means.

Firewall

A firewall is a piece of hardware or software that sits between two networks for security purposes. Typically, an organization might have its own computers linked in an Internet-like network called an intranet. A firewall is placed between this intranet and the Internet to prevent unauthorized users from gaining access to all the resources of the intranet. If you communicate with the Internet through a firewall, you must configure your Web browser to request Web pages from the firewalls proxy server, the program that filters packets of information between the intranet and the Internet. Ask your intranet or LAN administrator for instructions.

A firewall can serve the following functions:

• Limit Internet access to E-mail only, so that no other types of information can pass between the intranet and the Internet.
• Control who can telnet into your intranet (a method of logging in remotely).
• Limit what other kinds of traffic can pass between your intranet and the Internet etc.

A firewall can be simple or complex, depending on how specifically you want to control your Internet traffic. A simple firewall might require only that you configure the software in the router that connects your intranet to your ISP. A more complex firewall might be a computer running UNIX and specialized software. Firewall systems fall into two categories, network-level and application-level.

Network-Level Firewalls
These firewalls examine only the headers of each packet of information passing to or from the Internet. The firewall accepts or rejects packets based on the packets sender, receiver, and port. (Each Internet service, such as e-mail or the Web, has a different port number.) For example, the firewall might allow e-mail and Web packets to and from any computer on the intranet, but allow telnet (remote login) packets to and from only selected computers.

Application-Level Firewalls
These firewalls handle packets for each Internet service separately, usually by running a program called a proxy server, which accepts e-mail, Web, chat, newsgroup, and other packets from computers on the intranet, strips off the information that identifies the source of the packet, and passes it along to the Internet (or vice versa). When the replies return, the proxy server passes the replies back to the computer that sent the original message. To the rest of the Internet, all packets appear to be from the proxy server, so no information leaks out about the individual computers on your intranet. You can configure your proxy server to limit access to Internet services; for example, you can permit outbound telnet packets, so that your users can use telnet to log in to other computers, but refuse inbound telnet packets, so that no one on the Internet can log in to your intranets computers. A proxy server can also log all the packets that pass by, so that you have a record of who has access to your intranet from the Internet, and vice versa.

Web Server

A web server can be referred to as either the hardware, software or the computer application that helps to deliver content that can be accessed through the internet.

A web server is what makes it possible to be able to access content like web pages, or the other data from anywhere as long as it is connected to the internet. The hardware part is what houses the content, while the software part is what makes the content accessible through internet.

The most common use of web servers is to host websites, but there are other uses like data storage or for running enterprise application. There are also different ways to request content from a web server. The most common request is the Hypertext Transfer Protocol (HTTP), but there are also other requests like the Internet Message Access Protocol (IMAP) or the File Transfer Protocol (FTP).

Normally, a web server is an HTTP server and its function is to send information to the client software (usually a web browser) using the Hypertext transfer Protocol.

URL

Each stored file on the Internet has an address, called a Uniform Resource Locator (URL) that specifies where a known resource is available and the mechanism for retrieving it.
It gives the type and location of the resource. Each resource on the internet has its own URL means internet address. This help the user to identify the resource of any information on the internet.

The general form of the URL is :
protocol : // domain_name : port_no///#

URL is composed of six parts:
1. Protocol or data source
2. Domain name
3. Port address
4. Directory path
5. Object name
6. Spot

Protocol or data source: For network resources this is the name of the protocol used to access the required resources. By default http (Hypertext Transfer Protocol) is used in WWW. for retrieving and sending and searching.

Domain name: This is the domain name for the web server where the desire web page or the resources are present.

Domain name is another way of addressing by which we can identify and locate computers connected to the internet. Every computer on the internet has a unique IP address to distinguish it from one computer to another on the internet.

Port address: It is the address where the particular node is attached. By default it is 1.80 and it is not compulsory.

Directory path: This is the location of the web page in the web server file system.

Object name: This is the actual name of the HTML file.

Spot: This is the particular location of HTML file within the web page.

EDI (Electronic Data Interchange)

Electronic data interchange (EDI) is the structured transmission of data between organizations by electronic means. It is used to transfer electronic documents or business data from one computer system to another computer system, i.e. from one trading partner to another trading partner without human intervention.

EDI can be formally defined as 'The transfer of structured data, by agreed message standards, from one computer system to another without human intervention'.

EDI is the electronic transfer of a standardized business transaction between a sender and receiver computer, over some kind of private network or value added network (VAN). Both sides would have to have the same application software and the data would be exchanged in an extremely rigorous format. In sectors such as retail, automotive, defense and heavy manufacturing, EDI was developed to integrate information across larger parts of an organizations value chain from design to maintenance so that manufacturers could share information with designers, maintenance and other partners and stakeholders. Before the widespread uptake and commercial use of the Internet, the EDI system was very expensive to run mainly because of the high cost of the private networks.