> For the complete documentation index, see [llms.txt](https://docs.assenteo.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.assenteo.com/key-legislation/the-gdpr/is-your-business-a-data-controller-or-a-data-processor.md).

# Is your business a data controller or a data processor?

### Contents

* [1. What is a data controller?](#id-1.-what-is-a-data-controller)
* [2. What is a data processor?](#id-2.-what-is-a-data-processor)

### 1. What is a data controller?

If your business is **making decisions** about **what** personal data is processed, **why** it is processed, and **how** it is processed, then it is likely a **data controller** under the [GDPR](/key-legislation/the-gdpr.md).

* For example, if your business runs an app which collects patient symptoms to provide health recommendations, you decide **what** data to collect, **why** to collect it and **how** to collect it. This makes your business a **data controller**.&#x20;

### 2. What is a data processor?

If your business performs operations on personal data **on behalf** of a data controller (who has made the decisions about the whys and hows of that processing), it is a **data processor** under the [GDPR](/key-legislation/the-gdpr.md).&#x20;

* For example, if hospitals use your platform to store patient records, your business is processing personal data **on their behalf**. This makes your business a **data processor**.&#x20;

In practice, given the broad definition of processing, if your business is a data controller it is likely also a data processor. However, the processor role under the GDPR is really designed to capture a separate entity that processes personal data on the controller’s behalf.

* For example, if your app analyses patient symptoms using a third-party AI system, that AI system provider is working as your data processor.&#x20;

Data processors might also engage third parties to assist with data processing on behalf of the originaln controller. These entities are known as **subprocessors** under the GDPR. [Here](/key-legislation/the-gdpr/subprocessors-and-vendors.md), we explore the role and obligations of subprocessors and their linked controllers.&#x20;


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