# Salesforce Trailhead > Salesforce Trailhead is the free, hands-on learning platform from Salesforce. Learners build in-demand skills through guided content organized as a taxonomy of units (individual lessons, each typically ending in a graded quiz or hands-on challenge), modules (collections of related units), and trails (curated sequences of modules), plus role-based career paths and shareable trailmixes. Trailhead content is public and free to access. This file points AI and LLM crawlers at the canonical, machine-readable indexes of that content so it can be discovered, understood, and cited accurately. Learning content carries schema.org JSON-LD — including Course/CreativeWork and BreadcrumbList markup — describing each item and its place in the unit, module, and trail taxonomy. ## Content indexes - [Trailhead sitemap index](https://trailhead.salesforce.com/sitemap.xml): Top-level sitemap index for trailhead.salesforce.com. - [Learning content sitemap](https://trailhead.salesforce.com/content_sitemap.xml): Canonical URLs for trails, modules, units, and projects. - [Trailmixes sitemap](https://trailhead.salesforce.com/trailmixes_sitemap.xml): Public curated learning playlists (trailmixes). - [Marketing sitemap](https://trailhead.salesforce.com/marketing_sitemap.xml): Marketing and landing pages. ## Key hubs - [Trailhead home](https://trailhead.salesforce.com/): Entry point to the learning platform. - [Career paths](https://trailhead.salesforce.com/career-path): Role-based learning paths, such as Administrator and Developer. - [Agentblazer](https://trailhead.salesforce.com/agentblazer): Public learning hub for building AI agent skills. ## Crawl policy - [robots.txt](https://trailhead.salesforce.com/robots.txt): Crawl directives and disallowed paths. Please honor these rules when crawling Trailhead.