---
title: "Controller and processor"
description: "Under the GDPR the controller decides the purposes and means of processing and carries most duties; the processor acts on its documented instructions."
canonical: https://aigovernanceengineer.com/glossary/controller-and-processor
author: "Jorge García Aibar"
license: "CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)"
doi: https://doi.org/10.5281/zenodo.22956197
version: "0.5.0"
updated: 2026-09-25
---

# Controller and processor

Under the GDPR the controller decides the purposes and means of processing and carries most duties; the processor acts on its documented instructions [1]. An AI vendor serving your inference is usually a processor, but becomes a controller for any use of your data it decides on, such as training.

- Developed in: [ch. 19, Controller, processor or joint controller](https://aigovernanceengineer.com/bok/privacy-and-ai#controller-processor-or-joint-controller)
- Chapters: [ch. 19, Privacy & AI](https://aigovernanceengineer.com/bok/privacy-and-ai)
- Contrast with: [Sub-processor](https://aigovernanceengineer.com/glossary/sub-processor)
- In the glossary chapter: https://aigovernanceengineer.com/bok/glossary#t-controller-and-processor

## Sources

[1] Regulation (EU) 2016/679 (General Data Protection Regulation) (Arts. 4(1), 4(5), 4(7), 4(8), 4(12), 4(14), 5, 6, 9, 12(3), 22, 25, 28(2) and 28(4), 30, 33, 35; Recital 26). Publications Office of the EU (EUR-Lex). 2016-04-27. https://eur-lex.europa.eu/eli/reg/2016/679/oj/eng (verified: primary)