XML sitemaps can include lists of web pages, images, videos, and news articles. The standard sitemap.xml file lists regular URLs with optional priority and change frequency metadata. Beyond basic page URLs, you can specify image sitemaps that list image locations within pages, video sitemaps with thumbnail URLs and video metadata like duration and description, and news sitemaps for content published within the last 48 hours. The most common implementation is a standard URL list with last modification dates. For e-commerce sites, we typically include product pages, category pages, and high-value content pages while excluding low-value pages like thank-you pages, user account pages, or paginated URLs that don't add unique content. For sites with heavy media, image sitemaps help Google discover and index images that might otherwise be missed, especially important for product photography or portfolio sites. Video sitemaps require more metadata than standard URLs. You need to specify video title, description, thumbnail URL, duration, and publication date. This becomes critical for sites hosting video content directly rather than embedding YouTube or Vimeo players. News sitemaps follow a specific schema limited to articles published in the last two days and require publication name and date. At Ottawa SEO, we typically start with a standard sitemap for most clients and add image extensions for e-commerce sites. We cap sitemaps at 40,000 URLs per file rather than the 50,000 limit to leave buffer room and ensure reliable processing. If a site exceeds this, we implement a sitemap index file that references multiple sitemaps organized by content type or site section. The practical limit is what adds indexing value. Including every possible URL just bloats the file. We exclude thin content, duplicate pages, and URLs blocked by robots.txt. The sitemap should be a curated list of what you actually want indexed, not an exhaustive site dump. Most CMSs auto-generate sitemaps, but you need to audit what they include and prune aggressively for sites over 10,000 pages.