Sitelinks are the extra links Google sometimes displays beneath a site's main result, usually pointing to major sections like About, Contact, or a popular category, giving that one result significantly more space and visual weight on the page than a standard listing.
They're generated entirely by Google's own algorithm based on site structure, internal linking, and how people actually navigate a site; there's no way to directly request or manually configure them the way structured data can influence a rich snippet. What does influence eligibility indirectly is exactly the kind of technical fundamentals sitelinks reward: a clear, logical site structure, strong internal linking to a site's genuinely most important pages, and enough overall authority and brand recognition that Google is confident enough to expand the listing. Sitelinks appear most reliably for branded, navigational-intent searches, someone searching a company's name directly, which is why they're less something to actively chase and more a byproduct of a well-structured, established site that's already doing the fundamentals right.
