SEO, or Search Engine Optimization, is a crucial aspect of digital marketing aimed at improving a website's visibility in search engine results pages (SERPs). Its primary goal is to attract more organic (non-paid) traffic to a website by ensuring that the site ranks higher in search engine algorithms for relevant search queries.

SEO works through a combination of technical optimization, content creation, and link building. Firstly, technical SEO involves optimizing the structure and code of a website to make it easier for search engine crawlers to index and understand its content. This includes optimizing page speed, ensuring mobile-friendliness, and fixing any technical errors.

Secondly, content plays a vital role in SEO. Creating high-quality, relevant content that aligns with the interests and needs of the target audience helps in ranking for specific keywords. Keywords are terms or phrases users enter into search engines, and SEO involves researching these keywords and strategically placing them in website content.

Lastly, link building involves acquiring backlinks from other reputable websites. These links act as a vote of confidence for your site's authority and relevance in the eyes of search engines, thereby boosting rankings.

Overall, SEO is an ongoing process that requires continuous monitoring, tweaking, and adaptation to changes in search engine algorithms to maintain and improve rankings over time.