Web portal

A web portal is a site that provides a single function via a web page or site. Web portals often function as a point of access to information on the World Wide Web. Portals present information from diverse sources in an unified way. Aside from the search engine standard, web portals offer other services such as e-mail, news, stock prices, infotainment and various other features. Portals provide a way for enterprises to provide a consistent look and feel with access control and procedures for multiple applications, which otherwise would have been different entities altogether. An example of a web portal is Yahoo!
Two broad categorization of portals are a. Horizontal portals (e.g. Yahoo) b. Vertical portals (focused on one functional area. e.g., salesforce.com)
A personal portal is a site on the World Wide Web that typically provides personalized capabilities to its visitors, providing a pathway to other content. It is designed to use distributed applications, different numbers and types of middleware and hardware to provide services from a number of different sources. In addition, business portals are designed to share collaboration in workplaces. A further business-driven requirement of portals is that the content be able to work on multiple platforms such as personal computers, personal digital assistants (PDAs), and cell phones/mobile phones.
A personal or web portal can be integrated with many forum systems.

Why portals?

It is often necessary to have a centralized application that has access to various other applications within the same enterprise to share the information across the applications. Also the various users with different roles accessing the different applications prefer to have a single access point to all of them over the Internet. They like to personalize the applications and have the coupled applications coordinated. Above all, the administrator users like to have administrative tools all in a single place to administer all the applications. All these are achieved through portals. Since all the applications share information through portals, there is better communication between various types of users. Another advantage of portals is that they can make event-driven campaigns. Below is detailed list of advantages of using portals:
Intelligent integration and access to enterprise content, applications and processes
Improved communication and collaboration among customers, partners, and employees
Unified, real-time access to information held in disparate systems
Personalized user modification and maintenance of the website presentation
Below are the properties of portals:
Look and feel
Consistent headers and footers, color schemes, icons and logos which gives the user a feel and sense of consistency, uniformity, and ease of navigation
A portlet is an application within a browser window, displayed in an effective layout
A portlet is itself a web application
Portlets are aggregated by the portal page

Customization
Users control, on an individual basis, a portal’s look and feel by setting portlet layout, look and feel.

Development of personal portals
In the late 1990s, the web portal was a hot commodity. After the proliferation of web browsers in the mid-1990s, many companies tried to build or acquire a portal, to have a piece of the Internet market. The web portal gained special attention because it was, for many users, the starting point of their web browser. Netscape became a part of America Online, the Walt Disney Company launched Go.com, and Excite and @Home became a part of AT&T during the late 1990s. Lycos was said to be a good target for other media companies such as CBS.
Many of the portals started initially as either web directories (notably Yahoo!) and/or search engines (Excite, Lycos, AltaVista, infoseek, Hotbot, and Itsabove among the old ones). Expanding services was a strategy to secure the user-base and lengthen the time a user stayed on the portal. Services which require user registration such as free email, customization features, and chatrooms were considered to enhance repeat use of the portal. Game, chat, email, news, and other services also tend to make users stay longer, thereby increasing the advertising revenue.
The portal craze, with "old media" companies racing to outbid each other for Internet properties, died down with the dot-com flameout in 2000 and 2001. Disney pulled the plug on Go.com, Excite went bankrupt and its remains were sold to iWon.com. Some notable portal sites ― Yahoo!, for instance ― remain successful to this day. To modern dot-com businesses, the portal craze serves as a cautionary tale about the risks of rushing into a market crowded with highly-capitalized but largely undifferentiated me-too companies.
A leading academic institution portal framework is uPortal by JA-SIG.


Regional web portals
Along with the development and success of international personal portals such as Yahoo!, regional variants have also sprung up. Some regional portals contain local information such as weather forecasts, street maps and local business information. Another notable expansion over the past couple of years is the move into formerly unthinkable markets.
"Local content - global reach" portals have emerged not only from countries like Korea (Naver), India (Rediff), China (Sina.com), Romania(Neogen.ro), Greece(in.gr) and Italy (Webplace.it), but in countries like Vietnam where they are very important for learning how to apply e-commerce, e-government, etc. Such portals reach out to the widespread diaspora across the world.


Government web portals
At the end of the dot-com boom in the 1990s, many governments had already committed to creating portal sites for their citizens. In the United States the main portal is USA.gov, in addition to portals developed for specific audiences such as DisabilityInfo.gov; in the United Kingdom the main portals are Directgov (for citizens) and businesslink.gov.uk (for businesses).
Many U.S. states have their own portals which provide direct access to eCommerce applications (e.g., Hawaii Business Express and myIndianaLicense), agency and department web sites, and more specific information about living in, doing business in and getting around the state.
Many U.S. states have chosen to out-source the operation of their portals to third-party vendors. One company that is an example of this is NICUSA which runs 21 state portals.
The National Portal of India provides comprehensive, accurate, reliable and up-to-date information about India and its various facets.
One of the issues that comes up with government web portals is that different agencies often have their own portals and sometimes a statewide portal-directory structure is not sophisticated and deep enough to meet the needs of multiple agencies.


Corporate web portals
Corporate intranets gained popularity during the 1990s. Having access to a variety of company information via a web browser was a new way of working. Intranets quickly grew in size and complexity, and webmasters (many of whom lacked the discipline of managing content and users) became overwhelmed in their duties. It wasn't enough to have a consolidated view of company information, users were demanding personalization and customization. Webmasters, if skilled enough, were able to offer some capabilities, but for the most part ended up driving users away from using the intranet.
The 1990s were a time of innovation for the concept of corporate web portals. Many companies began to offer tools to help webmasters manage their data, applications and information more easily, and through personalized views. Some portal solutions today are able to integrate legacy applications, other portals objects, and handle thousands of user requests.
Today’s corporate portals are sprouting new value-added capabilities for businesses. Capabilities such as managing workflows, increasing collaboration between work groups, and allowing content creators to self-publish their information are lifting the burden off already strapped IT departments.
In addition, most portal solutions today, if architected correctly, can allow internal and external access to specific corporate information using secure authentication or Single sign-on.
JSR168 Standards emerged around 2001. Java Specification Request (JSR) 168 standards allow the interoperability of portlets across different portal platforms. These standards allow portal developers, administrators and consumers to integrate standards-based portals and portlets across a variety of vendor solutions.
Microsoft's SharePoint Portal Server line of products have been gaining popularity among corporations for building their portals, partly due to the tight integration with the rest of the Microsoft Office products. Research by Forrester Research in 2004 shows that Microsoft is the vendor of choice for companies looking for portal server software
In response to Microsoft's strong presence in the portal market, other portal vendors are being acquired, or are challenging their offering. Oracle Corporation, in 2007, released Web Center Suite, a similar product to SharePoint. Web Center Suite has a full line of collaboration tools (blogs, wikis, team spaces, calendaring, email, etc.).
In addition, the popularity of content aggregation is growing and portal solution will continue to evolve significantly over the next few years. The Gartner Group predicts generation 8 portals to expand on the enterprise mash-up concept of delivering a variety of information, tools, applications and access points through a single mechanism.
With the increase in user generated content, disparate data silo's, and file formats, information architects and taxonomist will be required to allow users the ability to tag (classify) the data. This will ultimately cause a ripple effect where users will also be generating adhoc navigation and information flows.
Some useful lessons can be learned from web 2.0 applications such as Netvibes, PageFlakes, Protopage and a new breed of competitors, such as PersonAll, use this angle to enter the market.


Hosted web portals
As corporate portals gained popularity a number of companies began offering them as a hosted service. The hosted portal market fundamentally changed the composition of portals. In many ways they served simply as a tool for publishing information instead of the loftier goals of integrating legacy applications or presenting correlated data from distributed databases. The early hosted portal companies such as Hyperoffice.com or the now defunct InternetPortal.com focused on collaboration and scheduling in addition to the distribution of corporate data. As hosted web portals have risen in popularity their feature set has grown to include hosted databases, document management, email, discussion forums and more. Hosted portals automatically personalize the content generated from their modules to provide a personalized experience to their users. In this regard they have remained true to the original goals of the earlier corporate web portals.

Domain specific portals
A number of portals have come about that are specific to the particular domain, offering access to related companies and services, a prime example of this trend would be the growth in property portals that give access to services such as estate agents, removal firm and solicitors that offer conveyancing.

Computer network

A computer network is an interconnected group of computers. Networks may be classified by the network layer at which they operate according to basic reference models considered as standards in the industry, such as the four-layer Internet Protocol Suite model. While the seven-layer Open Systems Interconnection (OSI) reference model is better known in academia, the majority of networks use the Internet Protocol Suite (IP).

Types of networks

Below is a list of the most common types of computer networks in order of scale.

Personal Area Network (PAN)

A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that may be used in a PAN are printers, fax machines, telephones, PDAs or scanners. The reach of a PAN is typically within about 20-30 feet (approximately 6-9 Meters).
Personal area networks may be wired with computer buses such as USB and FireWire. A wireless personal area network (WPAN) can also be made possible with network technologies such as IrDA and Bluetooth.

Local Area Network (LAN)

A network covering a small geographic area, like a home, office, or building. Current LANs are most likely to be based on Ethernet technology. For example, a library will have a wired or wireless LAN for users to interconnect local devices (e.g., printers and servers) and to connect to the internet. All of the PCs in the library are connected by category 5 (Cat5) cable, running the IEEE 802.3 protocol through a system of interconnection devices and eventually connect to the internet. The cables to the servers are on Cat 5e enhanced cable, which will support IEEE 802.3 at 1 Gbit/s.
The staff computers (bright green) can get to the color printer, checkout records, and the academic network and the Internet. All user computers can get to the Internet and the card catalog. Each workgroup can get to its local printer. Note that the printers are not accessible from outside their workgroup.

Typical library network, in a branching tree topology and controlled access to resources
All interconnected devices must understand the network layer (layer 3), because they are handling multiple subnets (the different colors). Those inside the library, which have only 10/100 Mbps Ethernet connections to the user device and a Gigabit Ethernet connection to the central router, could be called "layer 3 switches" because they only have Ethernet interfaces and must understand IP. It would be more correct to call them access routers, where the router at the top is a distribution router that connects to the Internet and academic networks' customer access routers.
The defining characteristics of LANs, in contrast to WANs (wide area networks), include their higher data transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines. Current Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to 10 Gbit/s. This is the data transfer rate. IEEE has projects investigating the standardization of 100 Gbit/s, and possibly 40 Gbit/s.

Campus Area Network (CAN)

A network that connects two or more LANs but that is limited to a specific and contiguous geographical area such as a college campus, industrial complex, or a military base. A CAN, may be considered a type of MAN (metropolitan area network), but is generally limited to an area that is smaller than a typical MAN. This term is most often used to discuss the implementation of networks for a contiguous area.

Metropolitan Area Network (MAN)

A Metropolitan Area Network is a network that connects two or more Local Area Networks or Campus Area Networks together but does not extend beyond the boundaries of the immediate town, city, or metropolitan area. Multiple routers, switches & hubs are connected to create a MAN.

Wide Area Network (WAN)

A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.

Global Area Network (GAN)

Global area networks (GAN) specifications are in development by several groups, and there is no common definition. In general, however, a GAN is a model for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc. The key challenge in mobile communications is "handing off" the user communications from one local coverage area to the next. In IEEE Project 802, this involves a succession of terrestrial Wireless local area networks (WLAN)