# Glossary

The terms below are the vocabulary of the [AI Inference](/en/documentation/platform/ai-inference/) documentation, and each definition links the page that carries the term.

| Term                     | Definition                                                                                                                                                                                                                                                                                                                                                                  |
| ------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| AI Inference             | The product that runs artificial intelligence models on Azion's globally distributed infrastructure in response to a request. [AI Inference](/en/documentation/platform/ai-inference/) calls each model through `Azion.AI.run` from inside a [function](/en/documentation/platform/functions/), so you provision no infrastructure to execute one.                          |
| AI Inference Starter Kit | The template that deploys an application with an OpenAI-compatible API in front of AI Inference. The [AI Inference Starter Kit](/en/documentation/guides/application-development/frameworks/ai-inference-starter-kit/) creates the application, the function that calls the model, and the Workload Domain that serves it.                                                  |
| Azion Cells              | The feature of [Orchestrator](/en/documentation/platform/orchestrator/) through which AI Inference runs a model. A call to `Azion.AI.run` reaches the model through the Azion Cells API.                                                                                                                                                                                    |
| Azion Runtime            | The execution environment for the JavaScript of a [function](/en/documentation/platform/functions/), built on Web standards. AI Inference models run on [Azion Runtime](/en/documentation/devtools/runtime/), and so does the function that calls them.                                                                                                                     |
| `Azion.AI.run`           | The runtime binding a [function](/en/documentation/platform/functions/) calls to run a model. It takes the model id and a body in the OpenAI request shape, and returns a response read from `choices[0].message.content`. [Model invocation](/en/documentation/platform/ai-inference/model-invocation/) documents every field of the body.                                 |
| Compute Time             | The usage meter for the execution of a model, stated in GB-hour. For AI Inference and LoRA Fine-Tune, it is the active execution time in hours multiplied by the memory allocated in gigabytes. The [pricing page](/en/documentation/fundamentals/pricing/#ai-inference) carries the rate.                                                                                  |
| LoRA Fine-Tune           | The add-on that extends [AI Inference](/en/documentation/platform/ai-inference/) with fine-tuning of supported models through Low-Rank Adaptation. [LoRA Fine-Tune](/en/documentation/platform/ai-inference/lora-fine-tune/) runs on Azion's infrastructure, and the [model pages](/en/documentation/platform/ai-inference/models/) state which models support it.          |
| model id                 | The string that identifies a model to `Azion.AI.run`, passed as its first argument. Two conventions are in use: the HuggingFace repository path, such as `Qwen/Qwen3-Embedding-4B`, and a lowercase form with no slash, such as `gpt-oss-20b`. Each [model page](/en/documentation/platform/ai-inference/models/) states the id to use for that model.                      |
| OpenAI-compatible API    | The request and response shape AI Inference accepts, matching the OpenAI chat completions format. The endpoint that serves it belongs to your own deployed application, on its Workload Domain, and AI Inference publishes no endpoint of its own. [Model invocation](/en/documentation/platform/ai-inference/model-invocation/) carries the request body and the response. |
| Workload Domain          | The domain Azion generates for an application, in the format `xxxxxxxxxx.map.azionedge.net`. An application deployed from the [AI Inference Starter Kit](/en/documentation/guides/application-development/frameworks/ai-inference-starter-kit/) serves its OpenAI-compatible endpoint on this domain. You can add a custom domain instead.                                  |