The Internet consists of thousands of networks world-wide, connecting research facilities, universities, libraries and private companies. Many of these networks have host computers dedicated to maintaining archives of information which are accessible to the public. The functions of the Internet may be divided into several categories.

A Source of Information

Internet services such as Newsgroups and the World Wide Web (WWW) hold vast amounts of information, much of which is freely accessible and available 24 hours per day. The information may be of varying quality but the diversity of available information is extraordinary; it includes IT, legal, financial, art, sport and entertainment.

Every piece of information stored on the Internet has a unique address known as a Uniform Resource Locator (URL). Search engines provide a mechanism for locating information.

While a lot of this information is freely available, it may also be viewed as a commodity and some information on the Internet is available only by subscription.

A Means of Communicating

Internet services such as Newsgroups and E-mail provide the Internet communications services.

The Internet is made up of thousands of networks located around the world, which are interconnected using routers and Wide Area Network (WAN) links. It is spread across more than 150 different countries with the Internet forming the largest WAN in existence.

There is no restriction on the type of operating system which may be used - any computer system can connect to the Internet either to provide information for others or to browse for information as a user.

All the diverse networks and systems are linked by common protocol (language); the TCP/IP transport protocol provides the means for communication, while application protocols such as SMTP, POP and NNTP provide the higher level services. Together, these protocols allow diverse systems to share data and to communicate.

Marketing - A Medium Through Which to Conduct Business

Through the development of e-commerce, the Internet has established an electronic global world-wide market that operates 24 hrs a day. Organizations and individuals are able to market goods and services, while purchasing is supported by facilities such as digital signatures and encryption. Developments in software mean that an increased number of facilities are becoming available all the time.

The mid-90s have seen the development and success of company Intranets. Internet technology has been applied to a LAN or WAN within an individual company, with the object of sharing information easily. Extranets have also been developed to allow organizations to share private information using the public Internet. Both Intranets and Extranets are discussed later in this module.

The rapid growth of the Internet has revealed weaknesses in its infrastructure and considerable investment is currently taking place to improve performance and reliability.

Internet Services The information services provided by the Internet are as follows:

• Internet E-mail
• Web pages and environment
• Chat and video conferencing
• News groups
• File Transfer Protocol (FTP)
• Databases for Information storage and retrieval (including search engines)
• Electronic commerce and inventory systems

Most of these applications use Client / Server technology, where a server holds and manages the content (such as web pages), and where software is used to request and display information.

Internet services were originally developed with a global network in mind, but they may also be used to support communications within an organization. The rapid growth in the use of Intranets has occurred as organizations adapt Internet technologies for use within a private network. Many of these Internet services are covered in detail later in the course.

Intranets

An Intranet may be defined as a private network (within an organization), which incorporates the processes, protocols and standards found on the World Wide Web. The growth of the Internet and the widespread acceptance of the technologies on which it is based have led network administrators to apply the same technologies to information systems within companies. The term ‘Intranet’ was not used until 1995; these networks were previously known as ‘Enterprise Internets’. Access is controlled by the organization and typically is limited to its employees. Intranets provide an important method of sharing information between employees.

Comparison Between an Intranet and the Internet

An Intranet differs from the Internet in the following ways:

• Whilst the Internet is vast and spans all countries, a typical Intranet is confined to a building or WAN. The Internet has more than 10,000,000 hosts while the largest Intranets would contain about 100,000 hosts.
• The Internet is a public information area and requires little security. An Intranet is private and security is normally important to a company. A user would expect to provide a login name and password when accessing an Intranet, whereas most of the Internet is freely available.
• The Internet has no owner and rules and standards are established by consensus. An Intranet is completely controlled and owned by the company within which it is located.

Why Use an Intranet?

The following reasons have contributed to the enormous growth in the use of Intranets:

• The technologies used within Intranets are very similar to those of the Internet. This makes it possible to transfer all the skills and software which have been developed for the Internet into this domain
• Users who already work with the Internet find the tools and software used on Intranets familiar
• The browser ‘front end’ is becoming the standard means of presenting data and many older applications are being re-written to meet this standard. For example, the use of IE4 in Windows 98 for displaying local, networked and world located files
• The cost and complexity of developing Intranets is usually less than that required for other types of network application. This is partly due to the wide availability of tools and technologies and also to the speed and simplicity of developing HTML applications
• Applications that have been developed for an Intranet can easily be adapted and expanded for use on the Internet. Information that is useful to employees may often be of interest to customers and information produced on the Intranet can rapidly be published on an Internet site if desired. This reduces the load on the Webmaster
• Intranets allow organizations to exploit information and knowledge such as documents and personal data
• Intranets may be used to reduce the amount of paper required in business procedures

Uses of an Intranet

The nature of the content on an Internet site is designed to attract customers and generate business for the company. Intranets are focused on sharing information within the company. Possible uses for an Intranet include:

• ensuring that up-to-date information is available for all employees
• linking to existing database and order processing systems to provide browser-based information for employees
• company telephone lists
• the staff restaurant menu
• a suggestion box for company policies
• FAQs
• new product information

As with the Internet, somebody must take responsibility for updating, removing and adding information. Intranets are only of value if they are accurate and up to date.

An organization can only derive the full benefit from an Intranet if an information sharing culture exists within that organization. In addition, users may require training both in Internet technology and in site organization and use.

Extranets

An Extranet is a collaborative network that uses Internet technology to link businesses with their suppliers, customers, or other businesses that share common goals. An Extranet may involve a private connection between two Intranets, or may be part of a company’s Intranet that is made accessible to authorized companies. The shared information can have various levels of accessibility to outsiders; for example, only collaborating parties should see financial information, while less sensitive information may be more widely accessible.

Extranet Applications

Like Intranet applications, those used on Extranets often integrate with existing inventory, production control and order processing applications. Examples of Extranet applications include:

• Paper-less transactions between customers and their suppliers. This was previously available to larger companies through Electronic Data Interchange (EDI), but the cost put it outside the reach of most companies
• Private newsgroups that co-operating companies use to share experiences and ideas
• Collaboration with other companies in joint development projects
• Training programs or other educational material that companies share
• Shared product catalogs accessible only to wholesalers or those "in the trade"
• Project management and control for companies that are part of a common work project

Extranets can provide a valuable means of improving relations with partners, customers and suppliers.

The term "Extranet" gives a name to a phenomenon that already existed informally in various inter-company GroupWare products. An Extranet usually necessitates security measures to prevent competitors from accessing sensitive information.

The security and privacy required for Extranets can be ensured through the use of a number of techniques, including:

• using transmission lines which are privately owned or leased
• tunneling through the Internet; for example, Point to Point Tunneling Protocol (PPTP) or Layer 2 Tunneling Protocol (L2TP), or creating a Virtual Private Network (VPN)
• using authentication with username and password
• using the Internet with encryption
• using digital signatures and certificates
• implementing firewalls; for example, blocking or allowing specific connections based on IP address