A para-site is a Web site that mainly depends on a typographical error, domain name mistake, or misspelling to attract people to its Web site. A para-site accomplishes this by choosing a domain name that is very similar to the intended site.
A para-site is so named because, just as a biological parasite feeds off of a host, these sites feed off other sites. In many cases, there may be little to no marketing associated with a para-site at all -- just a clever name. Some companies will buy domain names similar to their actual Web site just to keep a para-site from being able to take advantage of the name.
One of the most famous of these is whitehouse.org. While the official name of the chief executive's Web site is whitehouse.gov, anyone using the .org extension will find a much different site. Though the site has been toned down from its early days, it serves as a political commentary and satire site on the current occupant in the Oval Office.
While some para-sites can be harmless or even a little entertaining, others can be very harmful. Some may attempt to install viruses of spyware on your computer. These unintended consequences can often have severe consequences for your computer.
Some para-site Web sites can also be pornographic in nature. While this may be very offensive to some individuals, it has the potential to be quite startling to children, putting parents in the unenviable position of trying to explain to their young children what they saw. Because children often are not good spellers, this puts them at a much greater risk than the rest of the population to stumble across some of these sites.
In some cases, it may be possible to block a para-site using a type of Internet protection software, similar to what anti-virus and anti-spyware programs do. Some software companies list the most common para-sites and keep them on a list that prohibits access. This is done through a Host file, which serves kind of like an address book for URLs, blocking the bad ones and letting the good ones through.
While this may be a very effective tool, a para-site blocker should never replace a good virus and spyware protection program. New para-sites are being created everyday and the combinations are limited only by one's imagination.