mini MHA
health informatics

What is the Internet?

What is the Internet?

The Internet is a worldwide group of public and private computers linked together to exchange information. Its main purpose is to share information. Most often, that information is shared through the World Wide Web (WWW) or electronic mail (email). Other commonly-used services include newsgroups, file transfer, chatting, and searching. No one owns the Internet, nor is it controlled or regulated by anyone. It is a true universal, shared resource.

Physically, the Internet is a vast network of wires. Multiple high-speed "backbone" cables carry information to a series of other network cables (or nodes), which in turn carry information to smaller outlying cables, and so on. The set of rules for interactions between software programs on a network is called a protocol, which is simply a set of standardized communication conventions. More about how it works can be found here.

History of the Internet

E-Commerce: The Next Step

Electronic Commerce Database


All information sent through the Internet passes through several public networks. Without protection, people on those public networks could access to the information you are sending.

If you do not want "just anyone" to be able to access your information, you use specific security tools. For example, encryption, codes the information when you send it so that it looks meaningless to the average person. Only the designated recipient, who has the software to decrypt the information, can read it.

Netscape Communicator uses SSL (Secure Sockets Layers Protocol) to enhance Internet security. This public key encryption system uses pairs of digital keys (random strings of bytes) to protect the information. Your server site has one pair of keys and your computer has one pair of keys. The information is passed over a secure connection and then encrypted to protect the contents.

SSL also provides another level of security with site certification. Site certification means that every secure server must request and receive a unique digital certificate, which ensures that the site sending you a message is who they say they are (this information is called signed data). Netscape Communicator also allows you to have personal certificates that identify individuals who send information. Personal certificates are necessary when you want to send and receive encrypted email or access secure sites without a password. In Communicator, you set up your security preferences and check the security of Web sites using the Security button.

| Go to the Agenda | Go to Dr. Sauter's home page |

Page Owner: Professor Sauter (

© Vicki L. Sauter. All rights Reserved.