An IP address or Internet Protocol address is an address which allows one computer or other electronic device to recognize and communicate with another. Routers, telephones etc can also use IP addresses. Local Intranets can use IP addresses but they are best known on the Public Internet. An international organization allocates IP addresses to Internet Service Providers or ISPs. The ISPs in turn allocate IP addresses to their customers. An IP address can be static or dynamic. A static IP address is bound to a specific user, while a dynamic IP address may change its owners.
IP user locationEdit
As IP addresses are distributed to ISPs in ranges -- consecutive blocks of IP addresses, usually consisting of 256 or 65,536 addresses -- it's easy to find out which ISP serves a particular IP. A service called "whois" allows to perform such a search on an IP address.
This usually allows to find out in which city the user is actually located. Locating users with further precision is mostly impossible, as most ISPs use a single range for users in different regions of the city. Given that many ISPs give out dynamic IP addresses, finding a specific street/house location becomes pretty much impossible.
Of course, if the user visits a website through a proxy, he will be using the proxy's IP address.
IPs as a ban measureEdit
Quite often, IP addresses are used as a way of detecting banned users; while this is more secure than other methods (which may be easily circumvented), banning a dynamic IP address can lead to severe consequences:
If the other user suddenly gets the same IP that was banned, he will get banned on the website instead. The probability of two users from one ISP visiting the same website is slight with a small website like Liberapedia. This may often happen with more popular websites like Wikipedia. The original banned user, on the other hand, will be able to visit the website.
This is often resolved by banning not a single IP, but a whole range of IPs. This is even worse, as now all the users from that ISP will have trouble visiting the website. In the worst possible situations, a whole city or a small country can get banned entirely. Conservapedia has banned large areas frequently but most website administrators are more reasonable.
IP blocking on LiberapediaEdit