Search Engine Optimization (SEO) is the process of improving a website’s visibility and ranking on search engines like Google, Bing, or Yahoo to attract more organic (non-paid) traffic. It involves optimizing various elements of a website, including content, keywords, structure, speed, and backlinks, so that search engines can easily understand and recommend it to users. SEO is often divided into three main parts: on-page SEO, which focuses on optimizing content, titles, meta descriptions, and internal links; off-page SEO, which builds authority through backlinks and brand mentions; and technical SEO, which ensures smooth crawling, indexing, mobile-friendliness, and fast loading speed. The goal of SEO is to match user search intent, provide valuable information, and improve user experience, which leads to higher rankings and increased website traffic. Unlike paid advertising, SEO is a long-term strategy that builds credibility and trust over time, making it one of the most cost-effective digital marketing techniques for sustainable online growth.