Schema markup is code added to your website's HTML that tells search engines and AI crawlers what your content means, not just what it says. It uses the Schema.org vocabulary, a shared standard maintained by Google, Bing, Yahoo, and Yandex.
Without schema markup, a search engine reads raw text and makes its best guess. With schema markup, you explicitly state: "This is a LocalBusiness", "This is an FAQ", "This person is the founder". The result is richer search results, better AI citation, and stronger entity recognition.
Essential schema types for small business websites: (1) LocalBusiness or ProfessionalService on the homepage — your name, address, phone, area served, opening hours. (2) WebSite with SearchAction — enables sitelinks search box in Google results. (3) BreadcrumbList on all sub-pages — shows navigation path in search results. (4) FAQPage on any page with questions and answers. (5) Article or BlogPosting on every blog post. (6) Person for any founder or author content. (7) Service on service pages. (8) AggregateRating if you have real reviews.
The most common mistake is adding schema markup to only one page (usually the homepage) and leaving all other pages without it. Schema markup should be on every relevant page. A blog post without Article schema is a missed opportunity. A service page without Service and FAQPage schema is not communicating its full context to search engines.
Schema markup is also increasingly important for AI citation. When ChatGPT, Perplexity, or Claude answers a question using website content, they use schema markup to understand page context and decide what to quote. Speakable schema specifically tells AI systems which text is designed to be cited.