# About pipelines

> Document Understanding<sup>TM</sup> ML packages can run all three types of pipelines:

Document Understanding<sup>TM</sup> ML packages can run all three types of pipelines:

* [Training pipelines](https://docs.uipath.com/document-understanding/automation-suite/2023.10/classic-user-guide/training-pipelines#training-pipelines)
* [Evaluation pipelines](https://docs.uipath.com/document-understanding/automation-suite/2023.10/classic-user-guide/evaluation-pipelines#evaluation-pipelines)
* [Full pipelines](https://docs.uipath.com/document-understanding/automation-suite/2023.10/classic-user-guide/full-pipelines#full-pipelines)

Once completed, a pipeline run has associated outputs and logs. To check this information, in the **Pipelines** tab from the left sidebar, select a pipeline to open the **Pipeline view** which consists of:

* the **Pipeline details** such as type, ML Package name and version, dataset, GPU usage, parameters, and execution time
* the **Outputs** pane; this always includes a `_results.json` file containing a summary of the Pipeline details
* the **Logs** page; the logs can also be obtained in the **ML Logs** tab from the left sidebar

Training pipelines or Full pipelines can also be used to:

* [Fine-tune](https://docs.uipath.com/document-understanding/automation-suite/2023.10/classic-user-guide/fine-tuning#fine-tuning) ML models with data from Validation Station

## Terms and definitions

**Training:**

Training a model from scratch, i.e. using the **DocumentUnderstanding** ML Package in AI Center.

**Retraining:**

Training using a pre-trained base-model, i.e. using one of the other document extraction ML packages in AI Center such as **Invoices**, **Receipts**, **Purchase Orders**, etc.

**Auto-retraining:**

This is the name of an environment variable which can be set when creating a Pipeline in AI Center which enables the pipeline to automatically use the most recent exported dataset for training. This variable is independent of whether that dataset includes data from Validation Station or not.

**Fine-tuning:**

Training or retraining a model using a dataset which includes data coming from Validation Station.

**Auto-Fine-tuning:**

Using the Auto-retraining environment variable feature to automatically train a model using data fed in from Validation Station using the Scheduled Export feature of Document Manager.