Search engine optimization (SEO) is the practice of optimizing a website or webpage to improve its visibility and ranking in search engine results pages. The goal of SEO is to increase organic (non-paid) traffic to a website by making it more relevant and accessible to search engines and users.

SEO involves various techniques and strategies that are aimed at improving different aspects of a website, including its content, structure, and HTML source code. Here are some key elements and techniques commonly used in SEO.

1. Keyword Research: Identifying the right keywords that users are searching for and targeting those keywords in the website's content.
2. On-Page Optimization: Optimizing individual web pages to make them more search engine-friendly. This includes optimizing meta tags (title tags, meta descriptions), headings, URL structure, image tags, and overall content quality.
3. Technical SEO: Optimizing technical aspects of a website to ensure search engines can crawl and index it properly. This involves optimizing website speed, improving mobile-friendliness, fixing broken links, creating XML sitemaps, and implementing structured data markup.
4. Content Creation: Producing high-quality and relevant content that satisfies the search intent of users. Content should be informative, engaging, and optimized with targeted keywords.
5. Link Building: Acquiring high-quality backlinks from other reputable websites. Backlinks act as "votes of confidence" and can positively impact a website's search rankings.
6. User Experience (UX) Optimization: Enhancing user experience on the website, such as improving page load speed, navigation, mobile responsiveness, and overall website usability.
7. Local SEO: Optimizing a website to appear prominently in local search results. This is crucial for businesses targeting local customers.
8. Analytics and Monitoring: Tracking and analyzing website performance using tools like Google Analytics to gain insights into user behavior, keyword rankings, and traffic sources.