This article pertains to methods of hyperlinking to/of different websites, often used in regard to search engine optimization (SEO). Many techniques and special terminology about linking are described below.
A reciprocal link is a mutual link between two objects, commonly between two websites to ensure mutual traffic. have websites. If Bob's website links to Alice's website, and Alice's website links to Bob's website, the websites are reciprocally linked. Website owners often submit their sites to reciprocal link exchange directories, in order to achieve higher rankings in the search engines. Reciprocal linking between websites is an important part of the search engine optimization process because Google uses link popularity algorithms (defined as the number of links that led to a particular page and the anchor text of the link) to rank websites for relevancy.
Resource Links are a category of links, which can be either one-way or two-way, usually referenced as "Resources" or "Information" in navbars, but sometimes, especially in the early, less compartmentalized years of the Web, simply called "links". Basically, they are hyperlinks to a website or a specific webpage containing content believed to be beneficial, useful and relevant to visitors of the site establishing the link.
In recent years, resource links have grown in importance because most major search engines have made it plain that -- in Google's words -- "quantity, quality, and relevance of links count towards your rating."
The engines' insistence on resource links being relevant and beneficial developed because many of the methods described elsewhere in this article -- free-for-all linking, link doping, incestuous linking, overlinking, multi-way linking -- and similar schemes were employed solely to "spam" search-engines, i.e. to "fool" the engines' algorithms into awarding the sites employing these unethical devices undeservedly high page ranks and/or return positions.
Despite cautioning site developers (again quoting from Google) to avoid "'free-for-all' links, link popularity schemes, or submitting your site to thousands of search engines (because) these are typically useless exercises that don't affect your ranking in the results of the major search engines -- at least, not in a way you would likely consider to be positive," most major engines have deployed technology designed to "red flag" and potentially penalize sites employing such practices.
Forum signature linking
Forum signature linking is a technique used to build backlinks to a website. This is the process of using forum communities that allow outbound hyperlinks in their member's signature. This can be a fast method to build up inbound links to a website; it can also produce some targeted traffic if the website is relevant to the forum topic. It should be stated that forums using the nofollow attribute will have no actual Search Engine Optimization value.
Leaving a comment on a blog can result in a relevant do-follow link to the individual's website. Most of the time, however, leaving a comment on a blog turns into a no-follow link, which is almost useless in the eyes of search engines, such as Google and Yahoo! Search. On the other hand, most blog comments get clicked on by the readers of the blog if the comment is well-thought-out and pertains to the discussion of the other commenters and the post on the blog.
More Info : http://en.wikipedia.org/wiki/Methods_of_website_linking