Internet Security
Definitions
Firewall
A system designed to prevent unauthorized access to or from a private network.
Firewalls can be implemented in both hardware and software, or a combination
of both. Firewalls are frequently used to prevent unauthorized Internet users
from accessing private networks connected to the Internet, especially intranets.
All messages entering or leaving the intranet pass through the firewall, which
examines each message and blocks those that do not meet the specified security
criteria.
A firewall is considered a first line of defense in protecting private information.
Spam
Electronic junk mail or junk newsgroup postings. Some people define spam
even more generally as any unsolicited e-mail. Real spam is generally
e-mail advertising
for some product sent to a mailing list or newsgroup.
In addition to wasting people's time with unwanted e-mail, spam also eats up a lot of network bandwidth. Consequently, there are many organizations, as well as individuals, who have taken it upon themselves to fight spam with a variety of techniques. But because the Internet is public, there is really little that can be done to prevent spam, just as it is impossible to prevent junk mail.
Spyware
Spyware is any software which employs a user's Internet connection
in the background without their knowledge or explicit permission.
Silent background use of an Internet connection must be preceeded by a complete and truthful disclosure of proposed back channel usage, followed by the receipt of explicit, informed, consent for such use.
Any software communicating across the Internet without these elements is guilty of information theft and is properly known as Spyware.
Virus
A program or piece of code that is loaded onto your computer without your
knowledge and runs against your wishes. Viruses can also replicate themselves.
All computer viruses are manmade. A simple virus that can make a copy of
itself over and over again is relatively easy to produce. Even such a simple
virus is dangerous because it will quickly use all available memory and bring
the system to a halt. An even more dangerous type of virus is one capable
of transmitting itself across networks and bypassing security systems.
It is recommended that all users run up-to-date anti-virus software at all times. As a guide, updates to most anti-virus programs are released weekly.
Worm
A computer worm is a self-replicating computer program, similar to a computer
virus. A virus attaches itself to, and becomes part of, another executable
program; a worm is self-contained and does not need to be part of another
program to propagate itself.