A data controller refers to the person and/or organisation who decides for what purposes and how any personal data will be processed, whereas a data processor is any person and/or organisation who processes the data on behalf of the data controller. Example: your organisation (data controller) decides it wants to start sending out a monthly newsletter to its existing customers to keep them up to date with “latest news”. To do so, it needs the name and email address of its customers. You decide to use MailChimp (data processor) as the platform for you to use to design and distribute your monthly newsletter to your customers. Mailchimp (data processor) is processing the personal data of your customers on your behalf (data controller).