Technical SEO Glossary for Casino and Sportsbook Teams

Crawl budget: The set of URLs Google can and wants to crawl on a site, set by crawl capacity and crawl demand. Google says it mainly matters for very large or fast-changing sites. Crawl budget guide.
Crawl capacity limit: How much time Google's crawlers will spend holding connections to your server. It falls when the server returns 5xx errors or 429 responses.
Crawl demand: How much a crawler wants to fetch from a site, influenced by how popular and how frequently updated its URLs are.
Verified Googlebot: A request whose IP address resolves by reverse DNS to googlebot.com, google.com or googleusercontent.com and back again, or that matches Google's published crawler IP ranges. Server log guide.
Canonical URL: The URL Google selects to represent a group of duplicate or very similar pages. A rel=canonical tag states your preference; Google calls it a hint, not a rule. Canonical guide.
Duplicate cluster: The group of URLs Google treats as the same content, from which it picks one canonical. Google says pages can remain in a cluster for up to two weeks after the content issue is fixed.
Soft 404: A page that returns HTTP 200 but looks empty or like an error page, such as an ended promotion that says "offer not available". Google reports these separately and keeps crawling them.
noindex: A meta robots tag or X-Robots-Tag header that tells search engines not to index a page. It only works if the page can be crawled, so it must not be blocked by robots.txt.
robots.txt: A file at the root of each host that tells crawlers which paths they may fetch. It controls crawling, not indexing. Robots.txt rule explorer.
Orphan page: A page that exists and returns 200 but has no crawlable internal link pointing to it. Orphan pages guide.
Faceted navigation: Filters and sort options, such as provider, feature or volatility in a slots lobby, that create new URLs for each combination.
Rendering: The step where Google runs a page's JavaScript in a headless Chromium browser to see the final content. It is queued separately from crawling. JavaScript rendering guide.
Server-side rendering (SSR): Producing complete HTML on the server, so content and links are in the first response before any JavaScript runs.
Hydration: Client-side JavaScript taking over server-rendered HTML to make it interactive. A hydration mismatch means the server and browser produced different output.
Dynamic rendering: Serving prerendered HTML to bots and the normal app to users. Google calls it a workaround and not a recommended solution.
hreflang: An annotation that lists the language and regional versions of a page, so Google can show the right one. Each version must list itself and all others, and pairs must link back. Hreflang guide.
x-default: The hreflang value for the page to show when no listed language or region matches the user, often a country selector.
lastmod: The date in an XML sitemap entry showing when a page's content last changed. Google uses it only when it is consistently and verifiably accurate. Sitemap guide.
Domain property: A Search Console property verified by DNS that covers every subdomain and protocol of a domain. Subdomain guide.
Core Web Vitals: Google's user experience metrics: Largest Contentful Paint, Interaction to Next Paint and Cumulative Layout Shift, assessed at the 75th percentile of page loads. Checklist guide.