Structured data markup, or schema markup, helps search engines understand the content on a website and enhances local SEO by providing more relevant information to users in search results. For San Diego businesses, implementing local schema markup—such as business name, address, phone number, and reviews—can improve visibility in search features like rich snippets and local packs. This makes it easier for potential customers to find important business details directly on the search results page, driving more traffic to the site and improving local SEO rankings.