Link building involves creating relevant links to a website to improve search engine rankings and drive traffic. It can be done through guest posting, directory submissions, social media sharing, and profiles. A link's value depends on factors like page rank and whether it's a do-follow or no-follow link. Quality, relevant links associated with a brand are more important than sheer volume. Continued link building is necessary to maintain rankings as competition can rise. Certain types of paid links and those from meetups are acceptable, while bulk bought or spammy links provide little value. Great content and link building reinforce each other to maximize search visibility.