Internet – Part I

What is Internet? Internet is a global computer network of inter-connected networks.

All computers connected to the internet must communicate with each other using set of rules (protocols) called TCP/IP (Transmission Control Protocol/ Internet Protocol). Internet

Internet Activities Send and receive electronic messages ( ). Transfer data files to and from computers around the world (File Transfer Protocol [FTP])

View corporate or personal documents containing graphical hypertext content (World Wide Web). Internet Activities

Share point-of-view on specific subjects with other online groups, (Usenet news-groups - Network News Transfer Protocol). Internet Activities

Internet Addressing Each computer directly linked to the Internet must obtain a unique address so that it can be located.

A computers internet protocol (IP) address is a four-part series of numbers separated by periods. For example Internet Addressing

Because it is difficult to remember a long series of numbers, a name addressing system was developed, called domain name system (DNS), e.g. Whitehouse.gov Internet Addressing

The DNS is a world-wide system of databases that maps domain names with their corresponding IP address. Internet Addressing

To obtain an Internet domain name, it is necessary to register with (and pay) a special Internet committee, Internet Service Provider (ISP) Connection Access

Domain Names When an organization or company establishes a link to the Internet either as a high- speed, dedicated pointer itself or as an account through a dedicated provider, a domain name must be chosen.

The name is unique and comprised of these parts: ServerName.OrgName.OrgType.ContryName Domain Name

.jo: Jordan..uk: United Kingdom. Country Name:

. com: commercial organization..edu: education..int: international organization. Organization Type:

. mil: military organizations..org: nonprofit and research organizations..net: network and service operations. Organization Type:

Company or organization name: up to 22 alphanumeric characters and cannot include spaces (although underscore can be used). Organization Name:

Host computer Hostname Name:

This entire domain is part of LAN (Local Area Network) connected to the internet. The network server is connected to the Internet.

Each of the computers on the network gain their access to the Internet through the network server.

Electronic Mail ( ) Electronic mail, or , is a simple tool for exchanging messages between individuals or among larger audience.

Electronic Mail messages travel very quickly and inexpensively. The delivery of messages from one part of a country to another may take minutes.

Once a message has been received, it can be saved, printed, edited, forwarded to another user, or deleted. Electronic Mail

is becoming one of the most widely used services on the Internet Electronic Mail

1. Fast 2. Can save messages for future reference. 3. Free of charge. Get a free web-based account through Hotmail Electronic Mail

Address An address has two parts: 1. Username; 2. Domain Name.

Example

Messages Parts An message must have at least two parts: 1. Header; 2. Body.

Header The Header contains information about the message: sender, receiver, date and subject.

Message Body The body contains the actual message being sent.

Message Signature Sometimes, an message contains a third part, called the signature. It is optional, and usually identifies or provides information about the messages sender.

Which Program to use? 1. On UNIX you may use Pine or Mailx 2. Netscapes mail through Netscape Navigator.