> ## Documentation Index > Fetch the complete documentation index at: https://docs.enterspeed.com/llms.txt > Use this file to discover all available pages before exploring further. # Key concepts > The Speedtrain vocabulary — one page per concept, in the order they fit together. Speedtrain has a small vocabulary. These pages define each term precisely, in the order the concepts build on each other. Indexes and stage outputs — the data a task runs over. The versioned document describing one repeatable content job. Who the AI is, and which model it runs on. The dimensions the output varies across. Tools the model may call, and letting it see images. The rules that score every output. How scores aggregate into accept or reject. One run of a configuration over an input. Where accepted content is delivered. Connecting a source to a task for continuous processing. ## The one-sentence version A **task configuration** describes a content job. A **review session** runs a version of it over a **content source**, generating one output per item per **variant** combination. **Quality checks** score each output, a **quality gate** turns those scores into a verdict, a person decides, and accepted content goes to a **destination**.