I.T. Glossary Virus A program or piece of code that is loaded onto your computer and runs without your knowledge. 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. Trojan A destructive program that masquerades as a benign application. Unlike viruses, Trojan horses do not replicate themselves but they can be just as destructive. One of the most insidious types of Trojan horse is a program that claims to rid your computer of viruses but instead introduces them. Worm A program or algorithm that replicates itself over a computer network and usually performs malicious actions, such as using up the computer's resources and possibly shutting the system down. Spyware Any software that covertly gathers user information through the user's internet connection without his or her knowledge, usually for advertising purposes. Spyware applications are typically bundled as a hidden component of freeware or shareware programs that can be downloaded from the internet. Firewall A system designed to prevent unauthorised access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Wireless network / Wifi A method of connecting two or more computers together and allowing them to communicate with each other without wires or cables. IP Address An identifier for a computer or device on a TCP/IP network. Every device connected to the internet must have a unique address so that each piece of transferred data has a source and a destination. Back to list of services What people say about I.T. Guy Contact: T:  07775 621150 E: info@itguy.com