Link building is important for SEO and involves acquiring links from other websites to boost visibility and rankings. Effective modern link building focuses on creating high-quality content rather than accumulating large quantities of links, as search engines can identify and penalize manipulative tactics. Strong link building strategies include producing engaging content, guest blogging, identifying and replacing broken links, securing brand mentions, using PR, internal linking, and building relationships in the industry. The goal is to establish authority and credibility through valuable content that naturally attracts relevant backlinks over time.