Link-building is a famous SEO technique of attaining links from external websites to your own to improve both direct referrals (people clicking on the links) and search engine ranking. There are both paid and non-paid links.

Internet MarketingImportance of Link Building in SEO/Online Marketing

Link building technique is used for increasing the visibility and popularity of a product/service on internet by displaying the links of its website on other websites. The main purpose of linking a website (the targeted website) to other sites is to direct the visitors of those websites to the targeted website. This way it generates more visibility and more traffic.
Also, the website links on other sites show the search engine robots that the respective website is legitimate and deserves attention.
However, to actually gain from link building strategies, the links should be built with websites relevant to your own site. If the link building website is not related to your website, search engines consider it as spam or a black hat SEO.


Types of Link Building

One way Link building: It is a one way process where one site gets a link on another website due to the quality and usability purpose. The website whose link is posted need not provide exchange link of the site on which it is posted.

Reciprocal Link Building: It is a two way process where links are exchanged between two websites on one to one basis.
Three Way Link Exchange: It is a one way link exchange between three websites. Example- site A gives link to site B, site B to site C & site C to site A.