What is "nofollow"

nofollow is a value that can be assigned to the rel attribute of an HTML a element to instruct some search engines that the hyperlink should not influence the ranking of the link's target in the search engine's index. It is intended to reduce the effectiveness of certain types of internet advertising because their search algorithm depends heavily on the number of links to a website when determining which websites should be listed in what order in their search results for any given term. However, new information suggests that search engines will depend less on links in the future and more on other aspects.