IP address: Each computer that is connected to the Internet has a clearly identifiable, numeric address, the IP address, comprising four sequences of digits that are separated by periods, e.g.: 217.247.84.89 (example: T-Online). Static IP addresses enable the same computer to be contacted under the same address at any time (e.g., by a web server). Dynamic IP addresses are allocated for instance to T-Online customers dialing up to the Internet. They receive an unoccupied IP address which will not be the same every time.

Cache: Generally refers to an amount of quickly accessible memory in your computer. However, on the Web it more commonly refers to where the browser stores downloaded graphics on the user's computer. That way, when the user has to reload the graphics, the browser retrieves it from the computer much quicker than reloading it from the Internet.

DNS: Domain Name System, or by extension, Domain Name Services.

Traceroute: An operation of sending trace packets for determining information; traces the route of UDP packets for the local host to a remote host. Normally traceroute displays the time and location of the route taken to reach its destination computer.