In terms of data protection, the roles of the controller and processor are defined under the General Data Protection Regulation (GDPR), which is a legal framework that governs the processing of personal data within the European Union (EU) and the European Economic Area (EEA).

1. Controller: The controller is the entity or organization that determines the purposes, conditions, and means of the processing of personal data. In simpler terms, the controller is the one who decides why and how personal data is collected and processed. The controller has the primary responsibility for complying with data protection laws and ensuring that personal data is processed lawfully and securely. The controller's responsibilities include: a. Transparency and accountability: The controller must provide individuals with clear and accessible information about the processing of their personal data. This includes informing individuals about the purposes of processing, the legal basis for processing, and their rights in relation to their data. b. Lawful processing: The controller must ensure that personal data is processed based on a lawful basis, such as consent, contractual necessity, compliance with a legal obligation, protection of vital interests, performance of a task carried out in the public interest, or legitimate interests pursued by the controller or a third party. c. Data subject rights: The controller must enable individuals to exercise their rights regarding their personal data, such as the right to access, rectify, erase, restrict processing, object to processing, and data portability. d. Security and data breaches: The controller is responsible for implementing appropriate technical and organizational measures to ensure the security of personal data and for promptly notifying the supervisory authority and affected individuals in case of a data breach.
2. Processor: The processor is an entity or organization that processes personal data on behalf of the controller. The processor acts under the authority of the controller and processes personal data according to the controller's instructions. Processors can be external service providers or other entities within the same organization. The key responsibilities of the processor include: a. Data processing on behalf of the controller: The processor must process personal data only on the documented instructions of the controller, unless required to do so by law. Processors cannot use the personal data for their own purposes. b. Security and confidentiality: The processor must implement appropriate security measures to protect personal data and ensure the confidentiality, integrity, and availability of the data. c. Subprocessing: If the processor needs to engage another processor (subprocessor) to carry out specific processing activities, they must do so under a written agreement that imposes the same data protection obligations as the original contract between the controller and processor. d. Cooperation with the controller: The processor must assist the controller in fulfilling their data protection obligations, which may include providing information necessary for data protection impact assessments and cooperating with data protection authorities. e. Data breach notification: The processor must promptly notify the controller in case of a personal data breach.

It's important to note that under the GDPR, both the controller and processor have their own specific legal obligations and liabilities related to data protection. The GDPR aims to ensure that personal data is handled responsibly, securely, and in accordance with the rights of individuals.